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Sample records for aerosol exposure system

  1. Development and characterization of a resistance spot welding aerosol generator and inhalation exposure system.

    PubMed

    Afshari, Aliakbar; Zeidler-Erdely, Patti C; McKinney, Walter; Chen, Bean T; Jackson, Mark; Schwegler-Berry, Diane; Friend, Sherri; Cumpston, Amy; Cumpston, Jared L; Leonard, H Donny; Meighan, Terence G; Frazer, David G; Antonini, James M

    2014-10-01

    Limited information exists regarding the health risks associated with inhaling aerosols that are generated during resistance spot welding of metals treated with adhesives. Toxicology studies evaluating spot welding aerosols are non-existent. A resistance spot welding aerosol generator and inhalation exposure system was developed. The system was designed by directing strips of sheet metal that were treated with an adhesive to two electrodes of a spot welder. Spot welds were made at a specified distance from each other by a computer-controlled welding gun in a fume collection chamber. Different target aerosol concentrations were maintained within the exposure chamber during a 4-h exposure period. In addition, the exposure system was run in two modes, spark and no spark, which resulted in different chemical profiles and particle size distributions. Complex aerosols were produced that contained both metal particulates and volatile organic compounds (VOCs). Size distribution of the particles was multi-modal. The majority of particles were chain-like agglomerates of ultrafine primary particles. The submicron mode of agglomerated particles accounted for the largest portion of particles in terms of particle number. Metal expulsion during spot welding caused the formation of larger, more spherical particles (spatter). These spatter particles appeared in the micron size mode and accounted for the greatest amount of particles in terms of mass. With this system, it is possible to examine potential mechanisms by which spot welding aerosols can affect health, as well as assess which component of the aerosol may be responsible for adverse health outcomes.

  2. Computer-automated silica aerosol generator and animal inhalation exposure system

    PubMed Central

    McKinney, Walter; Chen, Bean; Schwegler-Berry, Diane; Frazer, Dave G.

    2015-01-01

    Inhalation exposure systems are necessary tools for determining the dose response relationship of inhaled toxicants under a variety of exposure conditions. The objective of this study was to develop an automated computer controlled system to expose small laboratory animals to precise concentrations of uniformly dispersed airborne silica particles. An acoustical aerosol generator was developed which was capable of re-suspending particles from bulk powder. The aerosolized silica output from the generator was introduced into the throat of a venturi tube. The turbulent high-velocity air stream within the venturi tube increased the dispersion of the re-suspended powder. That aerosol was then used to expose small laboratory animals to constant aerosol concentrations, up to 20mg/m3, for durations lasting up to 8h. Particle distribution and morphology of the silica aerosol delivered to the exposure chamber were characterized to verify that a fully dispersed and respirable aerosol was being produced. The inhalation exposure system utilized a combination of airflow controllers, particle monitors, data acquisition devices and custom software with automatic feedback control to achieve constant and repeatable exposure environments. The automatic control algorithm was capable of maintaining median aerosol concentrations to within ±0.2 mg/m3 of a user selected target concentration during exposures lasting from 2 to 8 h. The system was able to reach 95% of the desired target value in <10min during the beginning phase of an exposure. This exposure system provided a highly automated tool for conducting inhalation toxicology studies involving silica particles. PMID:23796015

  3. Design and testing of Electrostatic Aerosol in Vitro Exposure System (EAVES): an alternative exposure system for particles.

    PubMed

    de Bruijne, K; Ebersviller, S; Sexton, K G; Lake, S; Leith, D; Goodman, R; Jetters, J; Walters, G W; Doyle-Eisele, M; Woodside, R; Jeffries, H E; Jaspers, I

    2009-02-01

    Conventional in vitro exposure methods for cultured human lung cells rely on prior suspension of particles in a liquid medium; these have limitations for exposure intensity and may modify the particle composition. Here electrostatic precipitation was used as an effective method for such in vitro exposures. An obsolete electrostatic aerosol sampler was modified to provide a viable environment within the deposition field for human lung cells grown on membranous support. Particle deposition and particle-induced toxicological effects for a variety of particles including standardized polystyrene latex spheres (PSL) and diesel exhaust emission particle mixtures are reported. The Electrostatic Aerosol in Vitro Exposure System (EAVES) efficiently deposited particles from an air stream directly onto cells. Cells exposed to the electric field of the EAVES in clean air or in the presence of charged PSL spheres exhibited minimal cytotoxicity, and their release of inflammatory cytokines was indistinguishable from that of the controls. For the responses tested here, there are no significant adverse effects caused neither by the electric field alone nor by the mildly charged particles. Exposure to diesel exhaust emissions using the EAVES system induced a threefold increase in cytokines and cytotoxicity as compared to the control. Taken together, these data show that the EAVES can be used to expose human lung cells directly to particles without prior collection in media, thereby providing an efficient and effective alternative to the more conventional particle in vitro exposure methods.

  4. Design and performance of a recirculating radon-progeny aerosol generation and animal inhalation exposure system

    SciTech Connect

    Newton, G.J.; Cuddihy, R.G.; Yeh, H.C.; Boecker, B.B.

    1992-12-31

    At Inhalation Toxicology Research Institute we are conducting inhalation studies that expose laboratory animals to {sup 222}Rn progeny attached to vector aerosols typical of indoor and mine environments. These studies require exposures of up to 1500 working level months within a few hours. Thus, large amounts of {sup 226}Ra are needed to produce the gaseous {sup 222}Rn. A once-through exposure system was considered impractical because of statutory discharge limitations for radon and the large amounts of radium required. We therefore designed and constructed a recirculating exposure system that removes the aerosol after it has passed through the exposure chambers and recirculates the remaining purified radon. The purified radon and air mixture is then passed into a reaction aging chamber, where ingrowth of the progeny and their attachment to vector aerosols occur. The design includes (1) allowance for 45 mg {sup 226}Ra in the radon generator, (2) 40 L min{sup {minus}1} total flow rate, (3) CO{sub 2} removal, (4) reconstitution of oxygen tension and water vapor content to ambient levels, and (5) a trap for radon gas. Radon progeny exposure concentrations in the range of 5,000 to 100,000 working levels have been produced.

  5. Factors affecting the response of lung clearance systems to acid aerosols: role of exposure concentration, exposure time, and relative acidity.

    PubMed

    Schlesinger, R B

    1989-02-01

    The ability of the lungs to clear deposited material is essential for maintenance of lung homeostasis. Acid aerosols have been shown to alter the efficiency of this process. This paper assesses the role of acid aerosol exposure concentration (C), exposure time (T), and relative acidity in producing changes in clearance from both the tracheobronchial tree and respiratory region of the lungs of rabbits. The response was found to be due to total exposure, i.e., some combination form of C x T, and was also related to relative acidity.

  6. INDOOR AEROSOLS AND EXPOSURE ASSESSMENT

    EPA Science Inventory

    This chapter provides an overview of both indoor aerosol concentration measurements, and the considerations for assessment of exposure to aerosols in non-occupational settings. The fixed-location measurements of concentration at an outdoor location, while commuting inside an a...

  7. Characterization of a head-only aerosol exposure system for nonhuman primates.

    PubMed

    Dabisch, P A; Kline, J; Lewis, C; Yeager, J; Pitt, M L M

    2010-02-01

    A well-characterized exposure chamber is necessary to generate reproducible atmospheres for inhalation toxicology studies. The aim of the present study was to characterize a head-only exposure chamber for non-human primates. Aerosols containing bovine serum albumin (BSA) were used to characterize a 16-L dynamic airflow head-only exposure chamber. A 250-ml plastic bottle with a respirator attached located inside the chamber was used to simulate a breathing head. Chamber leak rate, mixing, and aerosol spatial distributions were quantified. The chamber concentration profile was measured at the chamber exhaust using an aerodynamic particle sizer. Aerosol spatial distribution was determined by collecting filter samples at several chamber locations. The particle size distribution was determined by collecting cascade impactor samples at several chamber locations. The estimated chamber leak rate was within standards suggested in the literature. The measured average aerosol residence time was similar to theoretical aerosol residence time, suggesting that the chamber was mixing well. Additionally, the average concentration measured at each of the sampling locations within the chamber was similar, and the within-run coefficients of variation (CV) across all sampling locations was similar to those reported in previously published studies, again suggesting that the aerosol concentration throughout the chamber was uniform. The particle size distribution was similar throughout the exposure chamber. Additionally, the BSA concentration and particle size distributions measured in the breathing zone of the simulated head were not significantly different from measurements made elsewhere in the chamber, suggesting that respiration does not affect the average aerosol concentration or particle size distribution at the mouth. PMID:20063997

  8. Exposures to acidic aerosols.

    PubMed

    Spengler, J D; Keeler, G J; Koutrakis, P; Ryan, P B; Raizenne, M; Franklin, C A

    1989-02-01

    Ambient monitoring of acid aerosols in four U.S. cities and in a rural region of southern Ontario clearly show distinct periods of strong acidity. Measurements made in Kingston, TN, and Steubenville, OH, resulted in 24-hr H+ ion concentrations exceeding 100 nmole/m3 more than 10 times during summer months. Periods of elevated acidic aerosols occur less frequently in winter months. The H+ determined during episodic conditions in southern Ontario indicates that respiratory tract deposition can exceed the effects level reported in clinical studies. Observed 12-hr H+ concentrations exceeded 550 nmole/m3 (approximately 27 micrograms/m3 H2SO4). The maximum estimated 1-hr concentration exceeded 1500 nmole/m3 for H+ ions. At these concentrations, an active child might receive more than 2000 nmole of H+ ion in 12 hr and in excess of 900 nmole during the hour when H2SO4 exceeded 50 micrograms/m3.

  9. Characterization of biological aerosol exposure risks from automobile air conditioning system.

    PubMed

    Li, Jing; Li, Mingzhen; Shen, Fangxia; Zou, Zhuanglei; Yao, Maosheng; Wu, Chang-yu

    2013-09-17

    Although use of automobile air conditioning (AC) was shown to reduce in-vehicle particle levels, the characterization of its microbial aerosol exposure risks is lacking. Here, both AC and engine filter dust samples were collected from 30 automobiles in four different geographical locations in China. Biological contents (bacteria, fungi, and endotoxin) were studied using culturing, high-throughput gene sequence, and Limulus amebocyte lysate (LAL) methods. In-vehicle viable bioaerosol concentrations were directly monitored using an ultraviolet aerodynamic particle sizer (UVAPS) before and after use of AC for 5, 10, and 15 min. Regardless of locations, the vehicle AC filter dusts were found to be laden with high levels of bacteria (up to 26,150 CFU/mg), fungi (up to 1287 CFU/mg), and endotoxin (up to 5527 EU/mg). More than 400 unique bacterial species, including human opportunistic pathogens, were detected in the filter dusts. In addition, allergenic fungal species were also found abundant. Surprisingly, unexpected fluorescent peaks around 2.5 μm were observed during the first 5 min use of AC, which was attributed to the reaerosolization of those filter-borne microbial agents. The information obtained here can assist in minimizing or preventing the respiratory allergy or infection risk from the use of automobile AC system.

  10. Whole-body nanoparticle aerosol inhalation exposures.

    PubMed

    Yi, Jinghai; Chen, Bean T; Schwegler-Berry, Diane; Frazer, Dave; Castranova, Vince; McBride, Carroll; Knuckles, Travis L; Stapleton, Phoebe A; Minarchick, Valerie C; Nurkiewicz, Timothy R

    2013-01-01

    Inhalation is the most likely exposure route for individuals working with aerosolizable engineered nano-materials (ENM). To properly perform nanoparticle inhalation toxicology studies, the aerosols in a chamber housing the experimental animals must have: 1) a steady concentration maintained at a desired level for the entire exposure period; 2) a homogenous composition free of contaminants; and 3) a stable size distribution with a geometric mean diameter < 200 nm and a geometric standard deviation σg < 2.5 (5). The generation of aerosols containing nanoparticles is quite challenging because nanoparticles easily agglomerate. This is largely due to very strong inter-particle forces and the formation of large fractal structures in tens or hundreds of microns in size (6), which are difficult to be broken up. Several common aerosol generators, including nebulizers, fluidized beds, Venturi aspirators and the Wright dust feed, were tested; however, none were able to produce nanoparticle aerosols which satisfy all criteria (5). A whole-body nanoparticle aerosol inhalation exposure system was fabricated, validated and utilized for nano-TiO2 inhalation toxicology studies. Critical components: 1) novel nano-TiO2 aerosol generator; 2) 0.5 m(3) whole-body inhalation exposure chamber; and 3) monitor and control system. Nano-TiO2 aerosols generated from bulk dry nano-TiO2 powders (primary diameter of 21 nm, bulk density of 3.8 g/cm(3)) were delivered into the exposure chamber at a flow rate of 90 LPM (10.8 air changes/hr). Particle size distribution and mass concentration profiles were measured continuously with a scanning mobility particle sizer (SMPS), and an electric low pressure impactor (ELPI). The aerosol mass concentration (C) was verified gravimetrically (mg/m(3)). The mass (M) of the collected particles was determined as M = (Mpost-Mpre), where Mpre and Mpost are masses of the filter before and after sampling (mg). The mass concentration was calculated as C = M

  11. Design and testing of electrostatic aerosol in vitro exposure system (EAVES): An alternative exposure system for particles

    EPA Science Inventory

    Conventional in vitro exposure methods for cultured human lung cells rely on prior suspension of particles in a liquid medium; these have limitations for exposure intensity and may modify the particle composition. Here electrostatic precipitation was used as an effective method f...

  12. A laboratory exposure system to study the effects of aging on super-micron aerosol particles

    SciTech Connect

    Santarpia, Joshua; Sanchez, Andres L.; Lucero, Gabriel Anthony; Servantes, Brandon Lee; Hubbard, Joshua Allen

    2014-02-01

    A laboratory system was constructed that allows the super-micron particles to be aged for long periods of time under conditions that can simulate a range of natural environments and conditions, including relative humidity, oxidizing chemicals, organics and simulated solar radiation. Two proof-of-concept experiments using a non-biological simulant for biological particles and a biological simulant demonstrate the utility of these types of aging experiments. Green Visolite®, which is often used as a tracer material for model validation experiments, does not degrade with exposure to simulated solar radiation, the actual biological material does. This would indicate that Visolite® should be a good tracer compound for mapping the extent of a biological release using fluorescence as an indicator, but that it should not be used to simulate the decay of a biological particle when exposed to sunlight. The decay in the fluorescence measured for B. thurengiensis is similar to what has been previously observed in outdoor environments.

  13. Improving performance of HVAC systems to reduce exposure to aerosolized infectious agents in buildings; recommendations to reduce risks posed by biological attacks.

    PubMed

    Hitchcock, Penny J; Mair, Michael; Inglesby, Thomas V; Gross, Jonathan; Henderson, D A; O'Toole, Tara; Ahern-Seronde, Joa; Bahnfleth, William P; Brennan, Terry; Burroughs, H E Barney; Davidson, Cliff; Delp, William; Ensor, David S; Gomory, Ralph; Olsiewski, Paula; Samet, Jonathan M; Smith, William M; Streifel, Andrew J; White, Ronald H; Woods, James E

    2006-01-01

    The prospect of biological attacks is a growing strategic threat. Covert aerosol attacks inside a building are of particular concern. In the summer of 2005, the Center for Biosecurity of the University of Pittsburgh Medical Center convened a Working Group to determine what steps could be taken to reduce the risk of exposure of building occupants after an aerosol release of a biological weapon. The Working Group was composed of subject matter experts in air filtration, building ventilation and pressurization, air conditioning and air distribution, biosecurity, building design and operation, building decontamination and restoration, economics, medicine, public health, and public policy. The group focused on functions of the heating, ventilation, and air conditioning systems in commercial or public buildings that could reduce the risk of exposure to deleterious aerosols following biological attacks. The Working Group's recommendations for building owners are based on the use of currently available, off-the-shelf technologies. These recommendations are modest in expense and could be implemented immediately. It is also the Working Group's judgment that the commitment and stewardship of a lead government agency is essential to secure the necessary financial and human resources and to plan and build a comprehensive, effective program to reduce exposure to aerosolized infectious agents in buildings.

  14. Acidic sulfate aerosols: characterization and exposure.

    PubMed

    Lioy, P J; Waldman, J M

    1989-02-01

    Exposures to acidic aerosol in the atmosphere are calculated from data reported in the scientific literature. The majority of date was not derived from studies necessarily designed to examine human exposures. Most of the studies were designed to investigate the characteristics of the atmosphere. However, the measurements were useful in defining two potential exposure situations: regional stagnation and transport conditions and local plume impacts. Levels of acidic aerosol in excess of 20 to 40 micrograms/m3 (as H2SO4) have been observed for time durations ranging from 1 to 12 hr. These were associated with high, but not necessarily the highest, atmospheric SO4(2)- levels. Exposures of 100 to 900 micrograms/m3/hr were calculated for the acid events that were monitored. In contrast, earlier London studies indicated that apparent acidity in excess of 100 micrograms/m3 (as H2SO4) was present in the atmosphere, and exposures less than 2000 micrograms/m3/hr were possible. Our present knowledge about the frequency, magnitude, and duration of acidic sulfate aerosol events and episodes is insufficient. Efforts must be made to gather more data, but these should be done in such a way that evaluation of human exposure is the focus of the research. In addition, further data are required on the mechanisms of formation of H2SO4 and on what factors can be used to predict acidic sulfate episodes.

  15. Acidic sulfate aerosols: characterization and exposure.

    PubMed Central

    Lioy, P J; Waldman, J M

    1989-01-01

    Exposures to acidic aerosol in the atmosphere are calculated from data reported in the scientific literature. The majority of date was not derived from studies necessarily designed to examine human exposures. Most of the studies were designed to investigate the characteristics of the atmosphere. However, the measurements were useful in defining two potential exposure situations: regional stagnation and transport conditions and local plume impacts. Levels of acidic aerosol in excess of 20 to 40 micrograms/m3 (as H2SO4) have been observed for time durations ranging from 1 to 12 hr. These were associated with high, but not necessarily the highest, atmospheric SO4(2)- levels. Exposures of 100 to 900 micrograms/m3/hr were calculated for the acid events that were monitored. In contrast, earlier London studies indicated that apparent acidity in excess of 100 micrograms/m3 (as H2SO4) was present in the atmosphere, and exposures less than 2000 micrograms/m3/hr were possible. Our present knowledge about the frequency, magnitude, and duration of acidic sulfate aerosol events and episodes is insufficient. Efforts must be made to gather more data, but these should be done in such a way that evaluation of human exposure is the focus of the research. In addition, further data are required on the mechanisms of formation of H2SO4 and on what factors can be used to predict acidic sulfate episodes. PMID:2651103

  16. Characterization of an aerosol chamber for human exposures to endotoxin.

    PubMed

    Taylor, L; Reist, P C; Boehlecke, B A; Jacobs, R R

    2000-03-01

    The objective of this study was to develop and characterize an exposure chamber in which human subjects could be exposed to low dust concentrations carrying an endotoxin coating. An exposure chamber, dust dispersion method, and endotoxin characterization technique were developed for inhalation exposures. A 6.27 m3 exposure chamber was designed and constructed from cinder block, glass windows, and Plexiglas. Using an acetone adhesion process, Enterobacter agglomerans were adsorbed onto respirable cellulose particles to create the endotoxin aerosol. The size distribution of the endotoxin-treated particles was verified using light microscopy and cascade impactors. A dry powder dust generator was refined to consistently disperse small quantities of the aerosol into the chamber to maintain dust concentrations at approximately 250 micrograms/m3. Dust levels during the chamber exposures were monitored using a portable continuous aerosol monitor (PCAM). During initial exposure runs, PCAM monitoring stations were positioned at different locations within a 0.5-meter matrix to document mixing patterns. Total dust and cascade impactor samples were collected throughout each exposure period to characterize the chamber operating system and insure the mean airborne dust concentration fulfilled target levels. A one-factor analysis of variance at the 95 percent confidence interval illustrated that there was not a statistically significant difference in the mean dust concentration throughout the exposure runs compared to the individual runs. Together the consistency of the total dust filters, endotoxin concentrations, and aerosol-monitoring instrument were adequate to allow use of the chamber for experimental studies involving human volunteers.

  17. Acidic sulfate aerosols: characterization and exposure

    SciTech Connect

    Lioy, P.J.; Waldman, J.M.

    1989-02-01

    Exposures to acidic aerosol in the atmosphere are calculated from data reported in the scientific literature. The majority of date was not derived from studies necessarily designed to examine human exposures. Most of the studies were designed to investigate the characteristics of the atmosphere. However, the measurements were useful in defining two potential exposure situations: regional stagnation and transport conditions and local plume impacts. Levels of acidicaerosol in excess of 20 to 40 micrograms/m/sup 3/ (as H/sub 2/SO/sub 4/) have been observed for time durations ranging from 1 to 12 hr. These were associated with high, but not necessarily the highest, atmospheric SO/sub 4/(2)- levels. Exposures of 100 to 900 micrograms/m/sup 3//hr were calculated for the acid events that were monitored. In contrast, earlier London studies indicated that apparent acidity in excess of 100 micrograms/m/sup 3/ (as H/sub 2/SO/sub 4/) was present in the atmosphere, and exposures less than 2000 micrograms/m/sup 3//hr were possible. Our present knowledge about the frequency, magnitude, and duration of acidic sulfate aerosol events and episodes is insufficient. Efforts must be made to gather more data, but these should be done in such a way that evaluation of human exposure is the focus of the research. In addition, further data are required on the mechanisms of formation of H/sub 2/SO/sub 4/ and on what factors can be used to predict acidic sulfate episodes. 96 references.

  18. A method for assessment of the genotoxicity of mainstream cigarette-smoke by use of the bacterial reverse-mutation assay and an aerosol-based exposure system.

    PubMed

    Kilford, Joanne; Thorne, David; Payne, Rebecca; Dalrymple, Annette; Clements, Julie; Meredith, Clive; Dillon, Debbie

    2014-07-15

    To date there are no widely accepted methods for the toxicological testing of complex gaseous mixtures and aerosols, such as cigarette smoke, although some modifications to the standard regulatory methods have been developed and used. Historically, routine testing of cigarettes has primarily focused on the particulate fraction of cigarette smoke. However, this fraction may not accurately reflect the full toxicity and mutagenicity of the smoke aerosol as a whole, which contains semi-volatiles and short-lived products of combustion. In this study we have used a modified version of the bacterial reverse-mutation (Ames) assay for the testing of mainstream smoke generated from 3R4F reference cigarettes with a Vitrocell(®) VC 10 exposure system. This method has been evaluated in four strains of Salmonella typhimurium (TA98, TA100, YG1024 and YG1042) and one strain of Escherichia coli (WP2 uvrA pKM101) in the absence and presence of a metabolic activation system. Following exposure at four concentrations of diluted mainstream cigarette-smoke, concentration-related and reproducible increases in the number of revertants were observed in all four Salmonella strains. E. coli strain WP2 uvrA pKM101 was unresponsive at the four concentrations tested. To quantify the exposure dose and to enable biological response to be plotted as a function of deposited mass, quartz-crystal microbalances were included in situ in the smoke-exposure set-up. This methodology was further assessed by comparing the responses of strain YG1042 to mainstream cigarette-smoke on a second VC 10 Smoking Robot. In summary, the Ames assay can be successfully modified to assess the toxicological impact of mainstream cigarette-smoke.

  19. Sampling port for real time analysis of bioaerosol in whole body exposure system for animal aerosol model development

    PubMed Central

    Saini, Divey; Hopkins, Gregory W.; Chen, Ching-ju; Seay, Sarah A.; Click, Eva M.; Lee, Sunhee; Hartings, Justin M.; Frothingham, Richard

    2010-01-01

    Introduction Multiple factors influence the viability of aerosolized bacteria. The delivery of aerosols is affected by chamber conditions (humidity, temperature, and pressure) and bioaerosol characteristics (particle number, particle size distribution, and viable aerosol concentration). Measurement of viable aerosol concentration and particle size is essential to optimize viability and lung delivery. The Madison chamber is widely used to expose small animals to infectious aerosols. Methods A multiplex sampling port was added to the Madison chamber to measure the chamber conditions and bioaerosol characteristics. Aerosols of three pathogens (Bacillus anthracis, Yersinia pestis, and Mycobacterium tuberculosis) were generated under constant conditions and their bioaerosol characteristics were analyzed. Airborne microbes were captured using an impinger or BioSampler. The particle size distribution of airborne microbes was determined using an aerodynamic particle sizer (APS). Viable aerosol concentration, spray factor (viable aerosol concentration/inoculum concentration), and dose presented to the mouse were calculated. Dose retention efficiency and viable aerosol retention rate were calculated from the sampler titers to determine the efficiency of microbe retention in lungs of mice. Results B. anthracis, Y. pestis, and M. tuberculosis aerosols were sampled through the port. The count mean aerodynamic sizes were 0.98, 0.77, and 0.78 μm with geometric standard deviations of 1.60, 1.90, and 2.37, and viable aerosol concentrations in the chamber were 211, 57, and 1 colony-forming unit (CFU)/mL, respectively. Based on the aerosol concentrations, the doses presented to mice for the three pathogens were 2.5e5, 2.2e4 and 464 CFU. Discussion Using the multiplex sampling port we determined whether the animals were challenged with an optimum bioaerosol based on dose presented and respirable particle size. PMID:20849964

  20. A System to Create Stable Nanoparticle Aerosols from Nanopowders.

    PubMed

    Ding, Yaobo; Riediker, Michael

    2016-01-01

    Nanoparticle aerosols released from nanopowders in workplaces are associated with human exposure and health risks. We developed a novel system, requiring minimal amounts of test materials (min. 200 mg), for studying powder aerosolization behavior and aerosol properties. The aerosolization procedure follows the concept of the fluidized-bed process, but occurs in the modified volume of a V-shaped aerosol generator. The airborne particle number concentration is adjustable by controlling the air flow rate. The system supplied stable aerosol generation rates and particle size distributions over long periods (0.5-2 hr and possibly longer), which are important, for example, to study aerosol behavior, but also for toxicological studies. Strict adherence to the operating procedures during the aerosolization experiments ensures the generation of reproducible test results. The critical steps in the standard protocol are the preparation of the material and setup, and the aerosolization operations themselves. The system can be used for experiments requiring stable aerosol concentrations and may also be an alternative method for testing dustiness. The controlled aerosolization made possible with this setup occurs using energy inputs (may be characterized by aerosolization air velocity) that are within the ranges commonly found in occupational environments where nanomaterial powders are handled. This setup and its operating protocol are thus helpful for human exposure and risk assessment. PMID:27501179

  1. Aerosol Observing System (AOS) Handbook

    SciTech Connect

    Jefferson, A

    2011-01-17

    The Aerosol Observing System (AOS) is a suite of in situ surface measurements of aerosol optical and cloud-forming properties. The instruments measure aerosol properties that influence the earth’s radiative balance. The primary optical measurements are those of the aerosol scattering and absorption coefficients as a function of particle size and radiation wavelength and cloud condensation nuclei (CCN) measurements as a function of percent supersaturation. Additional measurements include those of the particle number concentration and scattering hygroscopic growth. Aerosol optical measurements are useful for calculating parameters used in radiative forcing calculations such as the aerosol single-scattering albedo, asymmetry parameter, mass scattering efficiency, and hygroscopic growth. CCN measurements are important in cloud microphysical models to predict droplet formation.

  2. Exposure of acid aerosol for schoolchildren in metropolitan Taipei

    NASA Astrophysics Data System (ADS)

    Mao, I.-Fang; Lin, Chih-Hung; Lin, Chun-Ji; Chen, Yi-Ju; Sung, Fung-Chang; Chen, Mei-Lien

    Metropolitan Taipei, which is located in the subtropical area, is characterized by high population and automobile densities. For convenience, most primary schools are located near major roads. This study explores the exposure of acid aerosols for schoolchildren in areas in Taipei with different traffic densities. Acid aerosols were collected by using a honeycomb denuder filter pack sampling system (HDS). Experimental results indicated that the air pollutants were significantly correlated with traffic densities. The ambient air NO 2, SO 2, HNO 3, NO 3-, SO 42-, and aerosol acidity concentrations were 31.3 ppb, 4.7 ppb, 1.3 ppb, 1.9 μg m -3, 18.5 μg m -3, and 49.5 nmol m -3 in high traffic density areas, and 6.1 ppb, 1.8 ppb, 0.9 ppb, 0.7 μg m -3, 8.8 μg m -3 and 14.7 nmol m -3 in low traffic density areas. The exposure levels of acid aerosols for schoolchildren would be higher than the measurements because the sampling height was 5 m above the ground. The SO 2 levels were low (0.13-8.03 ppb) in the metropolitan Taipei. However, the SO 42- concentrations were relatively high, and might be attributed to natural emissions of sulfur-rich geothermal sources. The seasonal variations of acid aerosol concentrations were also observed. The high levels of acidic particles in spring time may be attributed to the Asian dust storm and low height of the mixture layer. We conclude that automobile contributed not only the primary pollutants but also the secondary acid aerosols through the photochemical reaction. Schoolchildren were exposed to twice the acid aerosol concentrations in high traffic density areas compared to those in low traffic density areas. The incidence of allergic rhinitis of schoolchildren in the high traffic density areas was the highest in spring time. Accompanied by high temperature variation and high levels of air pollution in spring, the health risk of schoolchildren had been observed.

  3. Lead exposures and biological responses in military weapons systems: Aerosol characteristics and acute lead effects among US Army artillerymen: Final report

    SciTech Connect

    Bhattacharyya, M.H.; Stebbings, J.H.; Peterson, D.P.; Johnson, S.A.; Kumar, R.; Goun, B.D.; Janssen, I.; Trier, J.E.

    1993-03-01

    This study was to determine the concentration and chemical nature of lead (Pb) aerosols produced during the firing of artillery and to determine the exposures and biological responses of crew members exposed to lead aerosols during such firing. The concentrations of lead-containing aerosols at crew positions depended on wind conditions, with higher concentrations when firing into a head wind. Aerosol concentrations were highest in the muzzle blast zone. Concentrations of lead in the blood of crew members rose during the first 12 days of exposure to elevated airborne lead concentrations and then leveled off. There was no rapid decrease in blood lead concentrations after completion of firing. Small decreases in hematocrit and small increases in free erythrocyte porphyrin were correlated with increasing exposure to airborne lead. These changes were reversed by seven weeks after firing. Changes in nerve conduction velocity had borderline statistical significance to airborne lead exposure. In measuring nerve conduction velocity, differences in skin temperature must be taken into account.

  4. Systemic immune cell response in rats after pulmonary exposure to manganese-containing particles collected from welding aerosols.

    PubMed

    Antonini, James M; Zeidler-Erdely, Patti C; Young, Shih-Houng; Roberts, Jenny R; Erdely, Aaron

    2012-01-01

    Welding fume inhalation affects the immune system of exposed workers. Manganese (Mn) in welding fume may induce immunosuppressive effects. The goal was to determine if Mn in welding fume alters immunity by reducing the number of circulating total leukocytes and specific leukocyte sub-populations. Sprague-Dawley rats were treated by intratracheal instillation (ITI) with either a single dose (2.00 mg/rat) or repeated doses (0.125 or 2.00 mg/rat for 7 weeks) with welding fumes that contained different levels of Mn. Additional rats were treated by ITI once a week for 7 weeks with the two doses of manganese chloride (MnCl₂). Bronchoalveolar lavage was performed to assess lung inflammation. Also, whole blood was recovered, and the number of circulating total leukocytes, as well as specific lymphocyte subsets, was determined by flow cytometry. The welding fume highest in Mn content significantly increased lung inflammation, injury, and production of inflammatory cytokines and chemokines compared to all other treatment groups. In addition, the same group expressed significant decreases in the number of circulating CD4⁺ and CD8⁺ T-lymphocytes after a single exposure, and significant reductions in the number of circulating total lymphocytes, primarily CD4⁺ and CD8⁺ T-lymphocytes, after repeated exposures (compared to control values). Repeated MnCl₂ exposure led to a trend of a reduction (but not statistically significant) in circulating total lymphocytes, attributable to the changes in the CD4⁺ T-lymphocyte population levels. The welding fume with the lower concentration of Mn had no significant effect on the numbers of blood lymphocytes and lymphocyte subsets compared to control values. Evidence from this study indicates that pulmonary exposure to certain welding fumes cause decrements in systemic immune cell populations, specifically circulating T-lymphocytes, and these alterations in immune cell number are not dependent exclusively on Mn, but likely a

  5. THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY (DEARS)

    EPA Science Inventory

    Field data collections for the Detroit Exposure and Aerosol Research Study (DEARS) have completed one-half of the planned study design. The DEARS is collecting personal, residential indoor, residential outdoor and central community monitoring data involving particulate matter, v...

  6. Long-term trends in exposures to nickel aerosols.

    PubMed

    Symanski, E; Chang, C C; Chan, W

    2000-01-01

    A comprehensive evaluation of temporal changes in exposure to nickel aerosols in the nickel-producing and nickel-using industries was conducted. For various nickel compounds, trends in the geometric mean exposure levels were evaluated on the basis of job group, building, plant, and industrial sector. At each level of classification, approximately two-thirds of the data provided evidence of workplace declines in exposures. Depending on how exposure measurements were aggregated, approximately one-quarter to one-half of the data produced statistically significant trends, with far more exposures declining than increasing over time. Whereas significantly negative linear trends were detected for total nickel exposures in the mining (-7%/yr), smelting (-9%/yr), and refining (-7%/yr) sectors, total nickel exposures in milling showed a significantly positive trend (+4%/yr). When the data were classified at the job group, building, or plant level, the median rate of change in exposure levels was -4, -6, and -3%/yr, respectively. For a subset of the data, effects of various factors related to work environment, process, and nature of the job on trends in exposure levels were evaluated. When such factors were examined simultaneously, the results suggested that the decline in exposures was greater in workplaces with no ventilation system compared with ventilated workplaces, in groups of workers who performed similar rather than diverse tasks, and in North American workplaces compared with workplaces in Europe and Western Australia. These results could be used in the design of prospective sampling protocols and in future retrospective health-effects studies of workers in the nickel industries.

  7. Long-term trends in exposures to nickel aerosols.

    PubMed

    Symanski, E; Chang, C C; Chan, W

    2000-01-01

    A comprehensive evaluation of temporal changes in exposure to nickel aerosols in the nickel-producing and nickel-using industries was conducted. For various nickel compounds, trends in the geometric mean exposure levels were evaluated on the basis of job group, building, plant, and industrial sector. At each level of classification, approximately two-thirds of the data provided evidence of workplace declines in exposures. Depending on how exposure measurements were aggregated, approximately one-quarter to one-half of the data produced statistically significant trends, with far more exposures declining than increasing over time. Whereas significantly negative linear trends were detected for total nickel exposures in the mining (-7%/yr), smelting (-9%/yr), and refining (-7%/yr) sectors, total nickel exposures in milling showed a significantly positive trend (+4%/yr). When the data were classified at the job group, building, or plant level, the median rate of change in exposure levels was -4, -6, and -3%/yr, respectively. For a subset of the data, effects of various factors related to work environment, process, and nature of the job on trends in exposure levels were evaluated. When such factors were examined simultaneously, the results suggested that the decline in exposures was greater in workplaces with no ventilation system compared with ventilated workplaces, in groups of workers who performed similar rather than diverse tasks, and in North American workplaces compared with workplaces in Europe and Western Australia. These results could be used in the design of prospective sampling protocols and in future retrospective health-effects studies of workers in the nickel industries. PMID:10885881

  8. Cellular Dose of Partly Soluble Cu Particle Aerosols at the Air–Liquid Interface Using an In Vitro Lung Cell Exposure System

    PubMed Central

    Cronholm, Pontus; Karlsson, Hanna L.; Midander, Klara; Odnevall Wallinder, Inger; Möller, Lennart

    2013-01-01

    Abstract Background There is currently a need to develop and test in vitro systems for predicting the toxicity of nanoparticles. One challenge is to determine the actual cellular dose of nanoparticles after exposure. Methods In this study, human epithelial lung cells (A549) were exposed to airborne Cu particles at the air–liquid interface (ALI). The cellular dose was determined for two different particle sizes at different deposition conditions, including constant and pulsed Cu aerosol flow. Results Airborne polydisperse particles with a geometric mean diameter (GMD) of 180 nm [geometric standard deviation (GSD) 1.5, concentration 105 particles/mL] deposited at the ALI yielded a cellular dose of 0.4–2.6 μg/cm2 at pulsed flow and 1.6–7.6 μg/cm2 at constant flow. Smaller polydisperse particles in the nanoregime (GMD 80 nm, GSD 1.5, concentration 107 particles/mL) resulted in a lower cellular dose of 0.01–0.05 μg/cm2 at pulsed flow, whereas no deposition was observed at constant flow. Exposure experiments with and without cells showed that the Cu particles were partly dissolved upon deposition on cells and in contact with medium. Conclusions Different cellular doses were obtained for the different Cu particle sizes (generated with different methods). Furthermore, the cellular doses were affected by the flow conditions in the cell exposure system and the solubility of Cu. The cellular doses of Cu presented here are the amount of Cu that remained on the cells after completion of an experiment. As Cu particles were partly dissolved, Cu (a nonnegligible contribution) was, in addition, present and analyzed in the nourishing medium present beneath the cells. This study presents cellular doses induced by Cu particles and demonstrates difficulties with deposition of nanoparticles at the ALI and of partially soluble particles. PMID:22889118

  9. Aerosol Inoculator for Exposure of Human Volunteers

    PubMed Central

    Gerone, Peter J.; Couch, Robert B.; Knight, Vernon

    1971-01-01

    The performance of an aerosol inoculator for human volunteers is described in tests that used the PR8 strain of type A influenza virus and sodium fluorescein as a physical tracer. Virus recovery from the aerosols was approximately 1% and was unaffected by such variables as prolonged aerosolization, total airflow, relative humidity, or method of sampling. The recovery of sodium fluorescein from the aerosol was approximately 12% and was influenced by total airflow rates and relative humidity. With this apparatus, it should be possible to deliver reasonably predictable and measurable doses of respiratory viruses to human subjects. The design makes it possible to dismantle the inoculator into its component parts to facilitate portability. Images PMID:5132095

  10. Nose-only exposure system for inhalation exposures of rodents to large particles.

    PubMed

    Yeh, H C; Snipes, M B; Brodbeck, R D

    1987-03-01

    A large-particle exposure system for small animals was designed, constructed and evaluated. The system was designed by incorporating a fluidized bed aerosol generator (FBG) and a nose-only exposure device to accommodate 40 small animals into a single unit. The system has four levels of exposure ports, each level having ten exposure ports radially positioned around the aerosol delivery components of the system. The aerosol generator produces aerosols that travel to the top of the system then downwards in order to be drawn past each animal's nose via vacuum ports immediately above the exposure ports. Nearly monodisperse polystyrene latex aerosols with nominal sizes of 3.0, 9.0 and 15.0 micron were generated as dry powders in an FBG with an inside diameter of 5 cm. During 60-min test runs, average aerosol mass concentrations up to 37 mg/m3 were achieved with less than 10% variation in mass concentration distribution throughout the unit.

  11. Development of an in vitro cytotoxicity model for aerosol exposure using 3D reconstructed human airway tissue; application for assessment of e-cigarette aerosol.

    PubMed

    Neilson, Louise; Mankus, Courtney; Thorne, David; Jackson, George; DeBay, Jason; Meredith, Clive

    2015-10-01

    Development of physiologically relevant test methods to analyse potential irritant effects to the respiratory tract caused by e-cigarette aerosols is required. This paper reports the method development and optimisation of an acute in vitro MTT cytotoxicity assay using human 3D reconstructed airway tissues and an aerosol exposure system. The EpiAirway™ tissue is a highly differentiated in vitro human airway culture derived from primary human tracheal/bronchial epithelial cells grown at the air-liquid interface, which can be exposed to aerosols generated by the VITROCELL® smoking robot. Method development was supported by understanding the compatibility of these tissues within the VITROCELL® system, in terms of airflow (L/min), vacuum rate (mL/min) and exposure time. Dosimetry tools (QCM) were used to measure deposited mass, to confirm the provision of e-cigarette aerosol to the tissues. EpiAirway™ tissues were exposed to cigarette smoke and aerosol generated from two commercial e-cigarettes for up to 6 h. Cigarette smoke reduced cell viability in a time dependent manner to 12% at 6 h. E-cigarette aerosol showed no such decrease in cell viability and displayed similar results to that of the untreated air controls. Applicability of the EpiAirway™ model and exposure system was demonstrated, showing little cytotoxicity from e-cigarette aerosol and different aerosol formulations when compared directly with reference cigarette smoke, over the same exposure time. PMID:26176715

  12. Airborne Atmospheric Aerosol Measurement System

    NASA Astrophysics Data System (ADS)

    Ahn, K.; Park, Y.; Eun, H.; Lee, H.

    2015-12-01

    It is important to understand the atmospheric aerosols compositions and size distributions since they greatly affect the environment and human health. Particles in the convection layer have been a great concern in global climate changes. To understand these characteristics satellite, aircraft, and radio sonde measurement methods have usually been used. An aircraft aerosol sampling using a filter and/or impactor was the method commonly used (Jay, 2003). However, the flight speed particle sampling had some technical limitations (Hermann, 2001). Moreover, the flight legal limit, altitude, prohibited airspace, flight time, and cost was another demerit. To overcome some of these restrictions, Tethered Balloon Package System (T.B.P.S.) and Recoverable Sonde System(R.S.S.) were developed with a very light optical particle counter (OPC), impactor, and condensation particle counter (CPC). Not only does it collect and measure atmospheric aerosols depending on altitudes, but it also monitors the atmospheric conditions, temperature, humidity, wind velocity, pressure, GPS data, during the measurement (Eun, 2013). In this research, atmospheric aerosol measurement using T.B.P.S. in Ansan area is performed and the measurement results will be presented. The system can also be mounted to an unmanned aerial vehicle (UAV) and create an aerial particle concentration map. Finally, we will present measurement data using Tethered Balloon Package System (T.B.P.S.) and R.S.S (Recoverable Sonde System).

  13. Sulfuric acid aerosol exposure in humans assessed by bronchoalveolar lavage

    SciTech Connect

    Frampton, M.W.; Voter, K.Z.; Morrow, P.E.; Roberts, N.J. Jr.; Culp, D.J.; Cox, C.; Utell, M.J. )

    1992-09-01

    Epidemiologic and experimental evidence suggests that exposure to acidic aerosols may affect human health. Brief exposures to acidic aerosols alter mucociliary clearance and increase airway responsiveness, but effects on host defense mechanisms at the alveolar level have not been studied in humans. Twelve healthy, nonsmoking volunteers between 20 and 39 yr of age were exposed for 2 h to aerosols of approximately 1,000 micrograms/m3 sulfuric acid (H2SO4) or sodium chloride (NaCl (control)), with intermittent exercise, in a randomized, double-blind fashion. Each subject received both exposures, separated by at least 2 wk. Bronchoalveolar lavage (BAL) was performed 18 h after exposure in order to detect evidence of an inflammatory response, changes in alveolar cell subpopulations, or changes in alveolar macrophage (AM) function, which is important in host defense. When compared with NaCl, exposure to H2SO4 did not increase polymorphonuclear leukocytes in BAL fluid. The percentage of T lymphocytes decreased in association with H2SO4 exposure, but the difference was not statistically significant (14.9% after NaCl, 11.5% after H2SO4; p = 0.14). Antibody-mediated cytotoxicity of AM increased in association with H2SO4 exposure (percent lysis 19.1 after NaCl, 23.6 after H2SO4; p = 0.16). No significant change was seen in release of superoxide anion or inactivation of influenza virus in vitro. Brief exposures to H2SO4 aerosol at 1,000 micrograms/m3 do not cause an influx of inflammatory cells into the alveolar space, and no evidence was found for alteration in antimicrobial defense 18 h after exposure.

  14. Overview of aerosolized Florida red tide toxins: exposures and effects.

    PubMed

    Fleming, Lora E; Backer, Lorraine C; Baden, Daniel G

    2005-05-01

    Florida red tide is caused by Karenia brevis, a dinoflagellate that periodically blooms, releasing its potent neurotoxin, brevetoxin, into the surrounding waters and air along the coast of the Gulf of Mexico. Exposure to Florida red tide toxins has been associated with adverse human health effects and massive fish and marine mammal deaths. The articles in this mini-monograph describe the ongoing interdisciplinary and interagency research program that characterizes the exposures and health effects of aerosolized Florida red tide toxins (brevetoxins). The interdisciplinary research program uses animal models and laboratory studies to develop hypotheses and apply these findings to in situ human exposures. Our ultimate goal is to develop appropriate prevention measures and medical interventions to mitigate or prevent adverse health effects from exposure to complex mixtures of aerosolized red tide toxins.

  15. (PORTUGAL)THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY

    EPA Science Inventory

    The Detroit Exposure and Aerosol Research Study (DEARS) represents an intensive examination of personal, residential and community-based particulate matter and related co-pollutant measurements in Detroit, Michigan. Data from the DEARS will be used as inputs into air quality, la...

  16. DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY

    EPA Science Inventory

    The DEARS is a three-year field monitoring study that will be conducted in Detroit, Michigan and is designed to measure exposure and describe exposure relationships for air toxics, PM components, PM from specific sources, and criteria pollutants. Detroit, Michigan was considered ...

  17. Characterizing Aerosolized Particulate As Part Of A Nanoprocess Exposure Assessment

    SciTech Connect

    Jankovic, John Timothy; Ogle, Burton R; Zontek, Tracy L; Hollenbeck, Scott M

    2010-01-01

    The purpose of this effort was to propose important aerosol characterization parameters that should be gathered as part of a nanomaterial hazard assessment and to offer a methodology for applying that data to daily operations. This study documents different ways of characterizing nanoscale materials using an aerosol from a process simulation consisting of a vacuum cleaner motor operating inside an enclosure. The aerosol is composed of insoluble carbon particles plus environmental background constituents. The average air concentration is 2.76E+5 p/cm3. Size measurements of the aerosol indicate > 70% of the particulate is blade-like in shape, 50% of which have a height dimension 100 nm. In terms of an equivalent spherical diameter 0.8% of the particulate is 100 nm in size. The carbon blades are characterized as having a root-mean-square roughness of 75 nm, and average fractal dimension of 2.25. These measures: aerosol chemistry, solubility, shape and size, surface area, number concentration and size distribution are important parameters to collect for current exposure assessment and toxicology and epidemiology studies.

  18. Aerosol sampling system

    DOEpatents

    Masquelier, Donald A.

    2004-02-10

    A system for sampling air and collecting particulate of a predetermined particle size range. A low pass section has an opening of a preselected size for gathering the air but excluding particles larger than the sample particles. An impactor section is connected to the low pass section and separates the air flow into a bypass air flow that does not contain the sample particles and a product air flow that does contain the sample particles. A wetted-wall cyclone collector, connected to the impactor section, receives the product air flow and traps the sample particles in a liquid.

  19. Commuter exposure to aerosol pollution on public transport in Singapore

    NASA Astrophysics Data System (ADS)

    Tan, S.; Velasco, E.; Roth, M.; Norford, L.

    2013-12-01

    Personal exposure to aerosol pollutants in the transport microenvironment of Singapore has not been well documented. Studies from many cities suggest that brief periods of exposure to high concentrations of airborne pollutants may have significant health impacts. Thus, a large proportion of aerosol exposure may be experienced during daily commuting trips due to the proximity to traffic. A better understanding of the variability across transport modes is therefore needed to design transport policies that minimize commuters' exposure. In light of this, personal exposure measurements of PM10 and PM2.5, particle number (PN), black carbon (BC), carbon monoxide (CO), particle-bound polycyclic aromatic hydrocarbons (pPAH), and active surface area (SA) were conducted on a selected route in downtown Singapore. Portable and real-time monitoring instruments were carried onto three different modes of public transport (bus, taxi, subway) and by foot. Simultaneous measurements were taken at a nearby park to capture the background concentrations. Large variability was observed amongst the various transport modes investigated. For example, the particle number concentration was on average 1.5, 1.6, 0.8, and 2.2 times higher inside buses, taxis, subway and by foot, respectively, than at the background site. Based on the results, it is possible to come up with a ranking of the 'cleanest' transport mode for Singapore.

  20. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    PubMed

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters.

  1. Aerosol generation by blower motors as a bias in assessing aerosol penetration into cabin filtration systems.

    PubMed

    Heitbrink, William A; Collingwood, Scott

    2005-01-01

    In cabin filtration systems, blower motors pressurize a vehicle cabin with clean filtered air and recirculate air through an air-conditioning evaporator coil and a heater core. The exposure reduction offered by these cabins is evaluated by optical particle counters that measure size-dependent aerosol concentration inside and outside the cabin. The ratio of the inside-to-outside concentration is termed penetration. Blower motors use stationary carbon brushes to transmit an electrical current through a rotating armature that abrades the carbon brushes. This creates airborne dust that may affect experimental evaluations of aerosol penetration. To evaluate the magnitude of these dust emissions, blower motors were placed in a test chamber and operated at 12 and 13.5 volts DC. A vacuum cleaner drew 76 m3/hour (45 cfm) of air through HEPA filters, the test chamber, and through a 5 cm diameter pipe. An optical particle counter drew air through an isokinetic sampling probe and measured the size-dependent particle concentrations from 0.3 to 15 microm. The concentration of blower motor aerosol was between 2 x 10(5) and 1.8 x 10(6) particles/m3. Aerosol penetration into three stationary vehicles, two pesticide application vehicles and one tractor were measured at two conditions: low concentration (outside in the winter) and high concentration (inside repair shops and burning incense sticks used as a supplemental aerosol source). For particles smaller than 1 microm, the in-cabin concentrations can be explained by the blower motor emissions. For particles larger than 1 microm, other aerosol sources, such as resuspended dirt, are present. Aerosol generated by the operation of the blower motor and by other sources can bias the exposure reduction measured by optical particle counters. PMID:15764523

  2. Pulmonary function and clearance after prolonged sulfuric acid aerosol exposure

    SciTech Connect

    Ives, P.J. ); Gerrity, T.R.; DeWitt, P.; Folinsbee, L.J. )

    1991-03-15

    The authors studied pulmonary function and clearance responses after a 4 H exposure to 75-100 {mu}g/m{sup 3} sulfuric acid aerosol (SAA). Healthy subjects, who exercised for 30 min/H at ventilation of about 25 L/min, were exposed once to clean air and once to SAA. Oral hygiene and acidic juice gargle were used to minimize oral ammonia. Lung function tests, including spirometry, plethysmography, and partial flow-volume (PEFV) curves were performed before and after exposure. Clearance of 99m-Technetium labeled iron oxide was assessed after each exposure. The first moment of fractional tracheobronchial retention (M1TBR), after correcting for 24 H retention and normalizing to time zero, was used as an index of clearance. There were no significant changes in lung volumes, airways resistance, or maximum expiratory flows after SAA exposure. Flow at 40% of total lung capacity on PEFV curves decreased 17% (NS) after SAA exposure. Tracheobronchial clearance was accelerated after a single exposure to SAA; M1TBR decreased from 73 {plus minus} 5 min (air) to 69 {plus minus} 5 min (SAA). These results suggest that acute prolonged exposure to low levels of SAA has minimal effects on lung mechanics in healthy subjects but does produce a modest acceleration of particle clearance.

  3. Photochemistry of Model Organic Aerosol Systems

    NASA Astrophysics Data System (ADS)

    Mang, S. A.; Bateman, A. P.; Dailo, M.; Do, T.; Nizkorodov, S. A.; Pan, X.; Underwood, J. S.; Walser, M. L.

    2007-05-01

    Up to 90 percent of urban aerosol particles have been shown to contain organic molecules. Reactions of these particles with atmospheric oxidants and/or sunlight result in large changes in their composition, toxicity, and ability to act as cloud condensation nuclei. For this reason, chemistry of model organic aerosol particles initiated by oxidation and direct photolysis is of great interest to atmospheric, climate, and health scientists. Most studies in this area have focused on identifying the products of oxidation of the organic aerosols, while the products of direct photolysis of the resulting molecules remaining in the aerosol particle have been left mostly unexplored. We have explored direct photolytic processes occurring in selected organic aerosol systems using infrared cavity ringdown spectroscopy to identify small gas phase products of photolysis, and mass-spectrometric and photometric techniques to study the condensed phase products. The first model system was secondary organic aerosol formed from the oxidation of several monoterpenes by ozone in the presence and absence of NOx, under different humidities. The second system modeled after oxidatively aged primary organic aerosol particles was a thin film of either alkanes or saturated fatty acids oxidized in several different ways, with the oxidation initiated by ozone, chlorine atom, or OH. In every case, the general conclusion was that the photochemical processing of model organic aerosols is significant. Such direct photolysis processes are believed to age organic aerosol particles on time scales that are short compared to the particles' atmospheric lifetimes.

  4. Susceptibility of Tribolium confusum (Coleoptera: Tenebrionidae) to pyrethrin aerosol: effects of aerosol particle size, concentration, and exposure conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A series of laboratory studies were conducted to assess effect of droplet size on efficacy of pyrethrin aerosol against adults of Tribolium confusum Jacqueline DuVal, the confused flour beetle. A vertical flow aerosol exposure chamber that generated a standardized particle size diameter was used for...

  5. Personal exposure to aerosolized red tide toxins (brevetoxins).

    PubMed

    Cheng, Yung Sung; Zhou, Yue; Naar, Jerome; Irvin, C Mitch; Su, Wei-Chung; Fleming, Lora E; Kirkpatrick, Barbara; Pierce, Richard H; Backer, Lorraine C; Baden, Daniel G

    2010-06-01

    Florida red tides occur annually in the Gulf of Mexico from blooms of the marine dinoflagellate, Karenia brevis, which produces highly potent natural polyether toxins, brevetoxins. Several epidemiologic studies have demonstrated that human exposure to red tide aerosol could result in increased respiratory symptoms. Environmental monitoring of aerosolized brevetoxins was performed using a high-volume sampler taken hourly at fixed locations on Siesta Beach, Florida. Personal exposure was monitored using personal air samplers and taking nasal swab samples from the subjects who were instructed to spend 1 hr on Sarasota Beach during two sampling periods of an active Florida red tide event in March 2005, and in May 2008 when there was no red tide. Results showed that the aerosolized brevetoxins from the personal sampler were in modest agreement with the environmental concentration taken from a high-volume sampler. Analysis of nasal swab samples for brevetoxins demonstrated 68% positive samples in the March 2005 sampling period when air concentrations of brevetoxins were between 50 to 120 ng/m(3) measured with the high-volume sampler. No swab samples showed detectable levels of brevetoxins in the May 2008 study, when all personal samples were below the limit of detection. However, there were no statistical correlations between the amounts of brevetoxins detected in the swab samples with either the environmental or personal concentration. Results showed that the personal sample might provide an estimate of individual exposure level. Nasal swab samples showed that brevetoxins indeed were inhaled and deposited in the nasal passage during the March 2005 red tide event.

  6. Multi-Sensor Aerosol Products Sampling System

    NASA Technical Reports Server (NTRS)

    Petrenko, M.; Ichoku, C.; Leptoukh, G.

    2011-01-01

    Global and local properties of atmospheric aerosols have been extensively observed and measured using both spaceborne and ground-based instruments, especially during the last decade. Unique properties retrieved by the different instruments contribute to an unprecedented availability of the most complete set of complimentary aerosol measurements ever acquired. However, some of these measurements remain underutilized, largely due to the complexities involved in analyzing them synergistically. To characterize the inconsistencies and bridge the gap that exists between the sensors, we have established a Multi-sensor Aerosol Products Sampling System (MAPSS), which consistently samples and generates the spatial statistics (mean, standard deviation, direction and rate of spatial variation, and spatial correlation coefficient) of aerosol products from multiple spacebome sensors, including MODIS (on Terra and Aqua), MISR, OMI, POLDER, CALIOP, and SeaWiFS. Samples of satellite aerosol products are extracted over Aerosol Robotic Network (AERONET) locations as well as over other locations of interest such as those with available ground-based aerosol observations. In this way, MAPSS enables a direct cross-characterization and data integration between Level-2 aerosol observations from multiple sensors. In addition, the available well-characterized co-located ground-based data provides the basis for the integrated validation of these products. This paper explains the sampling methodology and concepts used in MAPSS, and demonstrates specific examples of using MAPSS for an integrated analysis of multiple aerosol products.

  7. Effects of flame made zinc oxide particles in human lung cells - a comparison of aerosol and suspension exposures

    PubMed Central

    2012-01-01

    Background Predominantly, studies of nanoparticle (NPs) toxicology in vitro are based upon the exposure of submerged cell cultures to particle suspensions. Such an approach however, does not reflect particle inhalation. As a more realistic simulation of such a scenario, efforts were made towards direct delivery of aerosols to air-liquid-interface cultivated cell cultures by the use of aerosol exposure systems. This study aims to provide a direct comparison of the effects of zinc oxide (ZnO) NPs when delivered as either an aerosol, or in suspension to a triple cell co-culture model of the epithelial airway barrier. To ensure dose–equivalence, ZnO-deposition was determined in each exposure scenario by atomic absorption spectroscopy. Biological endpoints being investigated after 4 or 24h incubation include cytotoxicity, total reduced glutathione, induction of antioxidative genes such as heme-oxygenase 1 (HO–1) as well as the release of the (pro)-inflammatory cytokine TNFα. Results Off-gases released as by-product of flame ZnO synthesis caused a significant decrease of total reduced GSH and induced further the release of the cytokine TNFα, demonstrating the influence of the gas phase on aerosol toxicology. No direct effects could be attributed to ZnO particles. By performing suspension exposure to avoid the factor “flame-gases”, particle specific effects become apparent. Other parameters such as LDH and HO–1 were not influenced by gaseous compounds: Following aerosol exposure, LDH levels appeared elevated at both timepoints and the HO–1 transcript correlated positively with deposited ZnO-dose. Under submerged conditions, the HO–1 induction scheme deviated for 4 and 24h and increased extracellular LDH was found following 24h exposure. Conclusion In the current study, aerosol and suspension-exposure has been compared by exposing cell cultures to equivalent amounts of ZnO. Both exposure strategies differ fundamentally in their dose–response pattern

  8. Effects of in vitro and aerosol exposure to cadmium on phagocytosis by rat pulmonary macrophages

    SciTech Connect

    Greenspan, B.J.; Morrow, P.E.

    1984-01-01

    Aerosol exposures of rats were performed to assess the in vivo effects of cadmium on the phagocytosis of latex particles by pulmonary macrophages. An in vitro assay for particle uptake was devised which allowed quantification of phagocytosis by adhering and nonadhering macrophages. In vitro exposure to CdCl/sub 2/ caused dose-dependent decreases in viability (trypan blue exclusion), percentage cells with particles, total number of particles phagocytized, and the ability of the macrophages to adhere to a siliconized glass surface. In vivo effects were studied following 30-min aerosol exposures to 1.5 mg/m/sup 3/ Cd (MMAD = 0.35 ..mu..m, sigma/sub g/ =- 1.45) or 5.0 mg/m/sup 3/ Cd (MMAD = 0.45 ..mu..m, sigma/sub g/ = 1.60) as CdCl/sub 2/. Phagocytic activity in the in vitro test system was increased immediately and at Day 1 in the low exposure group. However, following exposure to 5.0 mg/m/sup 3/ Cd, phagocytic activity was depressed until 8 days postexposure. The results show that cadmium is capable of modifying the phagocytic ability of macrophages in vivo as well as in vitro. Determinations of the total number of particles phagocytized were found to be more sensitive than the percentage of cells phagocytizing in detecting the effects of cadmium exposure. 25 references, 4 figures, 3 tables.

  9. Nose-only exposure system for inhalation exposures of rodents to large particles

    SciTech Connect

    Yeh, H.C.; Snipes, M.B.; Brodbeck, R.D.

    1987-03-01

    A large-particle exposure system for animals was designed, constructed and evaluated. The system was designed by incorporating a fluidized bed aerosol generator (FBG) and a nose-only exposure device to accommodate 40 small animals into a single unit. The system has four levels of exposure ports, each level having ten exposure ports radially positioned around the aerosol delivery components of the system. The aerosol generator produces aerosols that travel to the top of the system then downwards in order to be drawn past each animal's nose via vacuum ports immediately above the exposure ports. Nearly monodisperse polystyrene latex aerosols with nominal sizes of 3.0, 9.0 and 15.0 ..mu..m were generated as dry powders in an FBG with an inside diameter of 5 cm. During 60-min test runs, average aerosol mass concentrations up to 37 mg/m/sup 3/ were achieved with less than 10% variation in mass concentration distribution throughout the unit.

  10. The NASA GEOS-5 Aerosol Forecasting System

    NASA Technical Reports Server (NTRS)

    Colarco, Peter; daSilva, Arlindo; Darmenov, Anton

    2011-01-01

    The NASA Goddard Earth Observing System modeling and data assimilation environment (GEOS-5) is maintained by the Global Modeling and Assimilation Office (GMAO) at the NASA Goddard Space Flight Center. Near-realtime meteorological forecasts are produced to support NASA satellite and field missions. We have implemented in this environment an aerosol module based on the Goddard Chemistry, Aerosol, Radiation, and Transport (GOCART) model. This modeling system has previously been evaluated in the context of hindcasts based on assimilated meteorology. Here we focus on the development and evaluation of the near-realtime forecasting system. We present a description of recent efforts to implement near-realtime biomass burning emissions derived from the Moderate Resolution Imaging Spectroradiometer (MODIS) fire radiative power products. We as well present a developing capability for improvement of aerosol forecasts by assimilation of aerosol information from MODIS.

  11. Indoor exposures to fine aerosols and acid gases.

    PubMed

    Koutrakis, P; Brauer, M; Briggs, S L; Leaderer, B P

    1991-11-01

    Indoor exposures to aerosols and gases are associated with both indoor and outdoor air pollution sources. The identification of sources and the assessment of their relative contribution can be a complicated process due to a) the presence of numerous indoor sources, which can vary from building to building; b) the uncertainties associated with the estimation of the impact of outdoor sources on indoor air quality; c) the interactions between pollutants; and d) the importance of reactions between pollutants and indoor surfaces. It is well established that fine particles (diameter less than or equal to 2.5 microns) originating from outdoor sources such as automobiles, oil and coal combustion, incineration, and diverse industrial activities can penetrate into the indoor environment. Indoor/outdoor ratios, usually varying between 0.4 and 0.8, depend on parameters such as particle size and density, air exchange rate, and the surface-to-volume ratio of the indoor environment. Determining fine particle elemental composition makes it possible to identify the contribution of different outdoor sources. This paper focuses on the origin and the concentration of indoor aerosols and acid gases by highlighting the results from two indoor air quality studies. PMID:1821374

  12. Exposure assessment of oxidant gases and acidic aerosols

    SciTech Connect

    Lioy, P.J.

    1989-01-01

    Clearly the presence of high ozone and acidic species in North America is primarily dependent upon photochemical air pollution. Evidence shows, however, that high acid exposures may occur in specific types of areas of high sulfur fuel use during the winter. At the present time, our concerns about exposure to local populations and regional populations should be directed primarily toward the outdoor activity patterns of individuals in the summer, and how those activity patterns relate to the location, duration, and concentrations of ozone and acid aerosol in photochemical air pollution episodes. Lioy Dyba and Mage et al have examined the activity patterns of children in summer camps. Because they spend more time outside than the normal population, these children form an important group of exercising individuals subject to photochemical pollution exposures. The dose of ozone inhaled by the children in the two camps was within 50% and 25% of the dose inhaled by adults in controlled clinical situations that produced clinically significant decrements in pulmonary function and increased the symptoms after 6.6 hr exposure in a given day. The chamber studies have used only ozone, whereas in the environment this effect may be enhanced by the presence of a complex mixture. The work of Lioy et al in Mendham, New Jersey found that hydrogen ion seemed to play a role in the inability of the children to return immediately to their normal peak expiratory flow rate after exposure. The camp health study conducted in Dunsville, Ontario suggested that children participating in a summer camp where moderate levels of ozone (100 ppb) but high levels of acid (46 micrograms/m3) occurred during an episode had a similar response. Thus, for children or exercising adults who are outdoors for at least one hour or more during a given day, the presence and persistence of oxidants in the environment are of particular concern. 63 references.

  13. Fabrication of vertical nanowire resonators for aerosol exposure assessment

    NASA Astrophysics Data System (ADS)

    Merzsch, Stephan; Wasisto, Hutomo Suryo; Stranz, Andrej; Hinze, Peter; Weimann, Thomas; Peiner, Erwin; Waag, Andreas

    2013-05-01

    Vertical silicon nanowire (SiNW) resonators are designed and fabricated in order to assess exposure to aerosol nanoparticles (NPs). To realize SiNW arrays, nanolithography and inductively coupled plasma (ICP) deep reactive ion etching (DRIE) at cryogenic temperature are utilized in a top-down fabrication of SiNW arrays which have high aspect ratios (i.e., up to 34). For nanolithography process, a resist film thickness of 350 nm is applied in a vacuum contact mode to serve as a mask. A pattern including various diameters and distances for creating pillars is used (i.e., 400 nm up to 5 μm). In dry etching process, the etch rate is set high of 1.5 μm/min to avoid underetching. The etch profiles of Si wires can be controlled aiming to have either perpendicularly, negatively or positively profiled sidewalls by adjusting the etching parameters (e.g., temperature and oxygen content). Moreover, to further miniaturize the wire, multiple sacrificial thermal oxidations and subsequent oxide stripping are used yielding SiNW arrays of 650 nm in diameter and 40 μm in length. In the resonant frequency test, a piezoelectric shear actuator is integrated with the SiNWs inside a scanning electron microscope (SEM) chamber. The observation of the SiNW deflections are performed and viewed from the topside of the SiNWs to reduce the measurement redundancy. Having a high deflection of ~10 μm during its resonant frequency of 452 kHz and a low mass of 31 pg, the proposed SiNW is potential for assisting the development of a portable aerosol resonant sensor.

  14. Acute Exposure from RADON-222 and Aerosols in Drinking Water

    NASA Astrophysics Data System (ADS)

    Bernhardt, George Paul, IV

    Radon-222 in water is released when the water is aerated, such as during showering. As a result, a temporary burst of radon-222 can appear as a short term, or acute, exposure. This study looked at homes with radon-222 concentrations in water from 800 picocuries per liter (pCi/l) to 53,000 pCi/l to determine the buildup of radon gas in a bathroom during showering. Samples from the tap and drain, compared to determine the percentage of radon-222 released, showed that between 58% and 88% of radon-222 in the water was released. The resultant radon-222 increase in air, measured with a flow-through detector, ranged from 2 pCi/l to 114 pCi/l in bathrooms due to a 10 to 15 minute shower with water flow rates ranging from 3 l/min to 6 l/min. Significantly, these rates did not fall rapidly but stayed approximately the same for up to 15 minutes after the water flow ceased. In examining exposures, the true danger is in the radon-222 progeny rather than the radon itself. The progeny can be inhaled and deposited in the tracheobronchial passages in the lung. Filter samples of bathroom air measured in a portable alpha spectrometer showed an increase in radon-222 progeny, notably polonium-218 and -214, in the air after showering. These increases were gradual and were on the order of 0.5 pCi/l at the highest level. Tap samples measured in a portable liquid scintillator showed that the progeny are present in the water but are not in true secular equilibrium with the radon-222 in the water. Therefore, the radon-222 does not have to decay to produce progeny since the progeny are already present in the water. A two stage sampler was used to examine the percentage of radiation available in aerosols smaller than 7 microns. Repeated trials showed that up to 85% of the radiation available in the aerosols is contained in the smaller, more respirable particles.

  15. Correlation of urinary nickel excretion with observed 'total' and inhalable aerosol exposures of nickel refinery workers.

    PubMed

    Werner, M A; Thomassen, Y; Hetland, S; Norseth, T; Berge, S R; Vincent, J H

    1999-12-01

    An investigation of the relationship between observed nickel aerosol exposures and urinary nickel excretion was undertaken at a Scandinavian nickel refinery. The goal of the study was to assess the impact of nickel aerosol speciation, the use of particle size-selective sampling instrumentation and adjustment of urinary levels for creatinine excretion on the usefulness of urinary nickel excretion as a marker for exposure. Urinary nickel measurements and paired 'total' and inhalable aerosol exposure measurements were collected each day for one week from refinery workers in four process areas. The mean observed urinary nickel concentration was 12 micrograms L-1 (11 micrograms of Ni per g of creatinine). The strongest relationships between urinary excretion and aerosol exposure were found when urinary nickel levels were adjusted for creatinine excretion and when exposure to only soluble forms of nickel aerosol was considered. No significant difference was observed between measures of 'total' and inhalable aerosol in the ability to predict urinary excretion patterns. In the light of these results, it is recommended that consideration be given to the chemical species distribution of nickel aerosol in the use of urinary nickel measurements as a screening tool for cancer risk in occupationally-exposed populations. PMID:11529189

  16. Aerosol dynamics and health: strategies to reduce exposure and harm.

    PubMed

    Rupp, Gerald

    2009-07-01

    The term 'air pollution' is used to describe the presence of chemicals or materials in the atmosphere that produce poor air quality. Air pollutants may be classified into four principal categories which include anthropogenic (man-made; e.g. combustion products), biogenic (biological; e.g. pollen, allergens), technogenic (technology; e.g. metal aerosols or smelter) and geogenic (geological; e.g. erosion of earth, i.e. minerals, volcanic ash). From these categories are derived the seven main pollutants of human health concern, i.e. carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide, hydrocarbons, lead, and particulate matter (PM). The common provenance of all these emissions is from the combustion of fossil fuels (e.g. coal, petrol and diesel), biomass (e.g. cooking) and tobacco smoke. PM is now considered to be the most precarious of pollutants, with the combustion-derived nano-particles being linked to a myriad of premature and excess deaths world-wide; especially for persons with pre-existing cardiovascular disorders. This meeting intended to bring together scientists from a host of disciplines (toxicologists, biologists, chemists, physicists and material scientists) that work at the bio-particulate interface. It aimed to present and discuss, via topical 'break-out' sessions, the current thoughts on the 'burden to human health' following exposure to and harm from combustion-derived particles. Furthermore, strategies for 'harm reduction' were another feature of this cross-disciplinary meeting. The final objectives were to identify biomarkers of exposure and harm to these inhalation hazards. All topics covered sought to find biomarker indices for human health effects.

  17. Aerosol dynamics and health: strategies to reduce exposure and harm.

    PubMed

    Rupp, Gerald

    2009-07-01

    The term 'air pollution' is used to describe the presence of chemicals or materials in the atmosphere that produce poor air quality. Air pollutants may be classified into four principal categories which include anthropogenic (man-made; e.g. combustion products), biogenic (biological; e.g. pollen, allergens), technogenic (technology; e.g. metal aerosols or smelter) and geogenic (geological; e.g. erosion of earth, i.e. minerals, volcanic ash). From these categories are derived the seven main pollutants of human health concern, i.e. carbon monoxide, nitrogen dioxide, ozone, sulphur dioxide, hydrocarbons, lead, and particulate matter (PM). The common provenance of all these emissions is from the combustion of fossil fuels (e.g. coal, petrol and diesel), biomass (e.g. cooking) and tobacco smoke. PM is now considered to be the most precarious of pollutants, with the combustion-derived nano-particles being linked to a myriad of premature and excess deaths world-wide; especially for persons with pre-existing cardiovascular disorders. This meeting intended to bring together scientists from a host of disciplines (toxicologists, biologists, chemists, physicists and material scientists) that work at the bio-particulate interface. It aimed to present and discuss, via topical 'break-out' sessions, the current thoughts on the 'burden to human health' following exposure to and harm from combustion-derived particles. Furthermore, strategies for 'harm reduction' were another feature of this cross-disciplinary meeting. The final objectives were to identify biomarkers of exposure and harm to these inhalation hazards. All topics covered sought to find biomarker indices for human health effects. PMID:19604050

  18. Recruitment and Retention Strategies for Environmental Exposure Studies: Lessons from the Detroit Exposure and Aerosol Research Study

    EPA Science Inventory

    The Environmental Protection Agency’s Detroit Exposure and Aerosol Research Study (DEARS) was a complex 3-year personal exposure study. The six geographically defined areas in the Detroit (Wayne County), Michigan, area used as study locations are ethnically diverse; the majority ...

  19. Virus-Like Particle Vaccination Protects Nonhuman Primates from Lethal Aerosol Exposure with Marburgvirus (VLP Vaccination Protects Macaques against Aerosol Challenges)

    PubMed Central

    Dye, John M.; Warfield, Kelly L.; Wells, Jay B.; Unfer, Robert C.; Shulenin, Sergey; Vu, Hong; Nichols, Donald K.; Aman, M. Javad; Bavari, Sina

    2016-01-01

    Marburg virus (MARV) was the first filovirus to be identified following an outbreak of viral hemorrhagic fever disease in Marburg, Germany in 1967. Due to several factors inherent to filoviruses, they are considered a potential bioweapon that could be disseminated via an aerosol route. Previous studies demonstrated that MARV virus-like particles (VLPs) containing the glycoprotein (GP), matrix protein VP40 and nucleoprotein (NP) generated using a baculovirus/insect cell expression system could protect macaques from subcutaneous (SQ) challenge with multiple species of marburgviruses. In the current study, the protective efficacy of the MARV VLPs in conjunction with two different adjuvants: QS-21, a saponin derivative, and poly I:C against homologous aerosol challenge was assessed in cynomolgus macaques. Antibody responses against the GP antigen were equivalent in all groups receiving MARV VLPs irrespective of the adjuvant; adjuvant only-vaccinated macaques did not demonstrate appreciable antibody responses. All macaques were subsequently challenged with lethal doses of MARV via aerosol or SQ as a positive control. All MARV VLP-vaccinated macaques survived either aerosol or SQ challenge while animals administered adjuvant only exhibited clinical signs and lesions consistent with MARV disease and were euthanized after meeting the predetermined criteria. Therefore, MARV VLPs induce IgG antibodies recognizing MARV GP and VP40 and protect cynomolgus macaques from an otherwise lethal aerosol exposure with MARV. PMID:27070636

  20. Radiological/biological/aerosol removal system

    DOEpatents

    Haslam, Jeffery J

    2015-03-17

    An air filter replacement system for existing buildings, vehicles, arenas, and other enclosed airspaces includes a replacement air filter for replacing a standard air filter. The replacement air filter has dimensions and air flow specifications that allow it to replace the standard air filter. The replacement air filter includes a filter material that removes radiological or biological or aerosol particles.

  1. Exposure of rhesus monkeys to cowpox virus Brighton Red by large-particle aerosol droplets results in an upper respiratory tract disease.

    PubMed

    Johnson, Reed F; Hammoud, Dima A; Perry, Donna L; Solomon, Jeffrey; Moore, Ian N; Lackemeyer, Matthew G; Bohannon, Jordan K; Sayre, Philip J; Minai, Mahnaz; Papaneri, Amy B; Hagen, Katie R; Janosko, Krisztina B; Jett, Catherine; Cooper, Kurt; Blaney, Joseph E; Jahrling, Peter B

    2016-08-01

    We previously demonstrated that small-particle (0.5-3.0 µm) aerosol infection of rhesus monkeys (Macaca mulatta) with cowpox virus (CPXV)-Brighton Red (BR) results in fulminant respiratory tract disease characterized by severe lung parenchymal pathology but only limited systemic virus dissemination and limited classic epidermal pox-like lesion development (Johnson et al., 2015). Based on these results, and to further develop CPXV as an improved model of human smallpox, we evaluated a novel large-particle aerosol (7.0-9.0 µm) exposure of rhesus monkeys to CPXV-BR and monitored for respiratory tract disease by serial computed tomography (CT). As expected, the upper respiratory tract and large airways were the major sites of virus-induced pathology following large-particle aerosol exposure. Large-particle aerosol CPXV exposure of rhesus macaques resulted in severe upper airway and large airway pathology with limited systemic dissemination. PMID:27166137

  2. A satellite view of aerosols in the climate system

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram J.; Tanre, Didier; Boucher, Olivier

    2002-01-01

    Anthropogenic aerosols are intricately linked to the climate system and to the hydrologic cycle. The net effect of aerosols is to cool the climate system by reflecting sunlight. Depending on their composition, aerosols can also absorb sunlight in the atmosphere, further cooling the surface but warming the atmosphere in the process. These effects of aerosols on the temperature profile, along with the role of aerosols as cloud condensation nuclei, impact the hydrologic cycle, through changes in cloud cover, cloud properties and precipitation. Unravelling these feedbacks is particularly difficult because aerosols take a multitude of shapes and forms, ranging from desert dust to urban pollution, and because aerosol concentrations vary strongly over time and space. To accurately study aerosol distribution and composition therefore requires continuous observations from satellites, networks of ground-based instruments and dedicated field experiments. Increases in aerosol concentration and changes in their composition, driven by industrialization and an expanding population, may adversely affect the Earth's climate and water supply.

  3. Characterization of a hooded human exposure apparatus for inhalation of gases and aerosols.

    PubMed

    O'Shaughnessy, Patrick T; Mehaffy, John; Watt, Janet; Sigurdarson, Sigurdur; Kline, Joel N

    2004-03-01

    A human exposure apparatus was designed to administer a gas and/or aerosol directly to the subject's face. This apparatus utilized a hood associated with a powered air-purifying respirator. The design criteria included the need to maximize subject comfort, maintain consistent atmospheres of a gas or dust within the hood, and the accurate use of direct-reading instruments to monitor exposure levels. An 83-L drum was used to pre-mix the gas or aerosol with the main dilution air prior to entering the hood worn by the subject. A clear plastic oxygen tent, ventilated with room exhaust air, was used to contain contaminants exiting the hood. Bypass valves were added to allow for a startup period during which contaminant concentration levels were allowed to stabilize prior to exposing the human subject. Results from characterization studies demonstrated that the system adequately contained contaminants within the oxygen tent, provided adequate mixing of contaminant and dilution air, produced stable contaminant concentrations over time, and was responsive to sudden changes in contaminant generation rate. PMID:15204873

  4. The Gillings Sampler--an electrostatic air sampler as an alternative method for aerosol in vitro exposure studies.

    PubMed

    Zavala, Jose; Lichtveld, Kim; Ebersviller, Seth; Carson, Johnny L; Walters, Glenn W; Jaspers, Ilona; Jeffries, Harvey E; Sexton, Kenneth G; Vizuete, William

    2014-09-01

    There is growing interest in studying the toxicity and health risk of exposure to multi-pollutant mixtures found in ambient air, and the U.S. Environmental Protection Agency (EPA) is moving towards setting standards for these types of mixtures. Additionally, the Health Effects Institute's strategic plan aims to develop and apply next-generation multi-pollutant approaches to understanding the health effects of air pollutants. There's increasing concern that conventional in vitro exposure methods are not adequate to meet EPA's strategic plan to demonstrate a direct link between air pollution and health effects. To meet the demand for new in vitro technology that better represents direct air-to-cell inhalation exposures, a new system that exposes cells at the air-liquid interface was developed. This new system, named the Gillings Sampler, is a modified two-stage electrostatic precipitator that provides a viable environment for cultured cells. Polystyrene latex spheres were used to determine deposition efficiencies (38-45%), while microscopy and imaging techniques were used to confirm uniform particle deposition. Negative control A549 cell exposures indicated the sampler can be operated for up to 4h without inducing any significant toxic effects on cells, as measured by lactate dehydrogenase (LDH) and interleukin-8 (IL-8). A novel positive aerosol control exposure method, consisting of a p-tolualdehyde (TOLALD) impregnated mineral oil aerosol (MOA), was developed to test this system. Exposures to the toxic MOA at a 1 ng/cm(2) dose of TOLALD yielded a reproducible 1.4 and 2-fold increase in LDH and IL-8 mRNA levels over controls. This new system is intended to be used as an alternative research tool for aerosol in vitro exposure studies. While further testing and optimization is still required to produce a "commercially ready" system, it serves as a stepping-stone in the development of cost-effective in vitro technology that can be made accessible to researchers in the

  5. Comparison of two in vitro systems to assess cellular effects of nanoparticles-containing aerosols

    PubMed Central

    Fröhlich, Eleonore; Bonstingl, Gudrun; Höfler, Anita; Meindl, Claudia; Leitinger, Gerd; Pieber, Thomas R.; Roblegg, Eva

    2013-01-01

    Inhalation treatment with nanoparticle containing aerosols appears a promising new therapeutic option but new formulations have to be assessed for efficacy and toxicity. We evaluated the utility of a VITROCELL®6 PT-CF + PARI LC SPRINT® Baby Nebulizer (PARI BOY) system compared with a conventional MicroSprayer. A549 cells were cultured in the air–liquid interface, exposed to nanoparticle aerosols and characterized by measurement of transepithelial electrical resistance and staining for tight junction proteins. Deposition and distribution rates of polystyrene particles and of carbon nanotubes on the cells were assessed. In addition, cytotoxicity of aerosols containing polystyrene particles was compared with cytotoxicity of polystyrene particles in suspension tested in submersed cultures. Exposure by itself in both exposure systems did not damage the cells. Deposition rates of aerosolized polystyrene particles were about 700 times and that of carbon nanotubes about 4 times higher in the MicroSprayer than in the VITROCELL®6 PT-CF system. Cytotoxicity of amine-functionalized polystyrene nanoparticles was significantly higher when applied as an aerosol on cell cultured in air–liquid interface culture compared with nanoparticle suspensions tested in submersed culture. The higher cytotoxicity of aerosolized nanoparticles underscores the importance of relevant exposure systems. PMID:22906573

  6. Nose-only exposure system

    DOEpatents

    Cannon, William C.; Bass, Edward W.; Decker, Jr., John R.

    1988-01-01

    An exposure system for supplying a gaseous material, i.e. an aerosol, gas or a vapor, directly to the noses of experimental animals includes concentric vertical inner and outer manifolds. The outer manifold connects with the necks of a large number of bottles in which the animals are confined with their noses adjacent the bottle necks. Readily detachable small tubes communicate with the inner manifold and extend to the necks of the bottles. The upper end of the outer manifold and the lower end of the inner manifold are closed. Gaseous material is supplied to the upper end of the inner manifold, flows through the small tubes to points adjacent the noses of the individual animals, then is drawn out through the bottom of the outer manifold. The bottles are readily removable and the device can be disassembled, e.g., for cleaning, by removing the bottles, removing the small tubes, and lifting the inner manifold from the outer manifold. The bottles are supported by engagement of their necks with the outer manifold supplemented, if additional support is required, by individual wire cradles. The outer ends of the bottles are closed by plugs, through which pass metal tubes which receive the tails of the animals (usually rodents) and which serve to dissipate body heat. The entire device is mounted for rotation on turntable bearings.

  7. Indoor aerosol modeling for assessment of exposure and respiratory tract deposited dose

    NASA Astrophysics Data System (ADS)

    Hussein, Tareq; Wierzbicka, Aneta; Löndahl, Jakob; Lazaridis, Mihalis; Hänninen, Otto

    2015-04-01

    Air pollution is one of the major environmental problems that influence people's health. Exposure to harmful particulate matter (PM) occurs both outdoors and indoors, but while people spend most of their time indoors, the indoor exposures tend to dominate. Moreover, higher PM concentrations due to indoor sources and tightness of indoor environments may substantially add to the outdoor originating exposures. Empirical and real-time assessment of human exposure is often impossible; therefore, indoor aerosol modeling (IAM) can be used as a superior method in exposure and health effects studies. This paper presents a simple approach in combining available aerosol-based modeling techniques to evaluate the real-time exposure and respiratory tract deposited dose based on particle size. Our simple approach consists of outdoor aerosol data base, IAM simulations, time-activity pattern data-base, physical-chemical properties of inhaled aerosols, and semi-empirical deposition fraction of aerosols in the respiratory tract. These modeling techniques allow the characterization of regional deposited dose in any metric: particle mass, particle number, and surface area. The first part of this presentation reviews recent advances in simple mass-balance based modeling methods that are needed in analyzing the health relevance of indoor exposures. The second part illustrates the use of IAM in the calculations of exposure and deposited dose. Contrary to previous methods, the approach presented is a real-time approach and it goes beyond the exposure assessment to provide the required information for the health risk assessment, which is the respiratory tract deposited dose. This simplified approach is foreseen to support epidemiological studies focusing on exposures originating from both indoor and outdoor sources.

  8. Associations between personal exposures to VOCs and alterations in cardiovascular physiology: Detroit Exposure and Aerosol Research Study (DEARS) - presentation

    EPA Science Inventory

    Introduction: An adult cohort consisting of 63 participants engaged in the US EPA’s recent Detroit Exposure and Aerosol Research Study (DEARS) and a University of Michigan cardiovascular sub-study conducted during summer and winter periods over 3 years between 2004 and 2007...

  9. Associations between Personal Exposures to VOCs and Alterations in Cardiovascular Physiology: Detroit Exposure and Aerosol Research Study (DEARS)

    EPA Science Inventory

    Background: An adult cohort consisting of 63 participants engaged in the US EPA’s recent Detroit Exposure and Aerosol Research Study (DEARS) and a University of Michigan cardiovascular sub-study conducted during summer and winter periods over 3 years between 2004 and 2007 (5 seas...

  10. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols.

  11. Aerosolized Red Tide Toxins (Brevetoxins) and Asthma: Continued health effects after 1 hour beach exposure.

    PubMed

    Kirkpatrick, Barbara; Fleming, Lora E; Bean, Judy A; Nierenberg, Kate; Backer, Lorraine C; Cheng, Yung Sung; Pierce, Richard; Reich, Andrew; Naar, Jerome; Wanner, Adam; Abraham, William M; Zhou, Yue; Hollenbeck, Julie; Baden, Daniel G

    2011-01-01

    Blooms of the toxic dinoflagellate, Karenia brevis, produce potent neurotoxins in marine aerosols. Recent studies have demonstrated acute changes in both symptoms and pulmonary function in asthmatics after only 1 hour of beach exposure to these aerosols. This study investigated if there were latent and/or sustained effects in asthmatics in the days following the initial beach exposure during periods with and without an active Florida red tide.Symptom data and spirometry data were collected before and after 1 hour of beach exposure. Subjects kept daily symptom diaries and measured their peak flow each morning for 5 days following beach exposure. During non-exposure periods, there were no significant changes in symptoms or pulmonary function either acutely or over 5 days of follow-up. After the beach exposure during an active Florida red tide, subjects had elevated mean symptoms which did not return to the pre-exposure baseline for at least 4 days. The peak flow measurements decreased after the initial beach exposure, decreased further within 24 hours, and continued to be suppressed even after 5 days. Asthmatics may continue to have increased symptoms and delayed respiratory function suppression for several days after 1 hour of exposure to the Florida red tide toxin aerosols. PMID:21499552

  12. Ionization detection system for aerosols

    DOEpatents

    Jacobs, Martin E.

    1977-01-01

    This invention relates to an improved smoke-detection system of the ionization-chamber type. In the preferred embodiment, the system utilizes a conventional detector head comprising a measuring ionization chamber, a reference ionization chamber, and a normally non-conductive gas triode for discharging when a threshold concentration of airborne particulates is present in the measuring chamber. The improved system utilizes a measuring ionization chamber which is modified to minimize false alarms and reductions in sensitivity resulting from changes in ambient temperature. In the preferred form of the modification, an annular radiation shield is mounted about the usual radiation source provided to effect ionization in the measuring chamber. The shield is supported by a bimetallic strip which flexes in response to changes in ambient temperature, moving the shield relative to the source so as to vary the radiative area of the source in a manner offsetting temperature-induced variations in the sensitivity of the chamber.

  13. Clinical and Pathological Findings Associated with Aerosol Exposure of Macaques to Ricin Toxin

    PubMed Central

    Pincus, Seth H.; Bhaskaran, Manoj; Brey, Robert N.; Didier, Peter J.; Doyle-Meyers, Lara A.; Roy, Chad J.

    2015-01-01

    Ricin is a potential bioweapon that could be used against civilian and military personnel. Aerosol exposure is the most likely route of contact to ricin toxin that will result in the most severe toxicity. Early recognition of ricin exposure is essential if specific antidotes are to be applied. Initial diagnosis will most likely be syndromic, i.e., fitting clinical and laboratory signs into a pattern which then will guide the choice of more specific diagnostic assays and therapeutic interventions. We have studied the pathology of ricin toxin in rhesus macaques exposed to lethal and sublethal ricin aerosols. Animals exposed to lethal ricin aerosols were followed clinically using telemetry, by clinical laboratory analyses and by post-mortem examination. Animals exposed to lethal aerosolized ricin developed fever associated with thermal instability, tachycardia, and dyspnea. In the peripheral blood a marked neutrophilia (without immature bands) developed at 24 h. This was accompanied by an increase in monocytes, but depletion of lymphocytes. Red cell indices indicated hemoconcentration, as did serum chemistries, with modest increases in sodium and blood urea nitrogen (BUN). Serum albumin was strikingly decreased. These observations are consistent with the pathological observations of fluid shifts to the lungs, in the form of hemorrhages, inflammatory exudates, and tissue edema. In macaques exposed to sublethal aerosols of ricin, late pathologic consequences included chronic pulmonary fibrosis, likely mediated by M2 macrophages. Early administration of supportive therapy, specific antidotes after exposure or vaccines prior to exposure have the potential to favorably alter this outcome. PMID:26067369

  14. Characterization of Marine Aerosol for Assessment of Human Exposure to Brevetoxins

    PubMed Central

    Cheng, Yung Sung; Zhou, Yue; Irvin, Clinton M.; Pierce, Richard H.; Naar, Jerome; Backer, Lorraine C.; Fleming, Lora E.; Kirkpatrick, Barbara; Baden, Dan G.

    2005-01-01

    Red tides in the Gulf of Mexico are commonly formed by the fish-killing dinoflagellate Karenia brevis, which produces nine potent polyether brevetoxins (PbTxs). Brevetoxins can be transferred from water to air in wind-powered white-capped waves. Inhalation exposure to marine aerosol containing brevetoxins causes respiratory symptoms. We describe detailed characterization of aerosols during an epidemiologic study of occupational exposure to Florida red tide aerosol in terms of its concentration, toxin profile, and particle size distribution. This information is essential in understanding its source, assessing exposure to people, and estimating dose of inhaled aerosols. Environmental sampling confirmed the presence of brevetoxins in water and air during a red tide exposure period (September 2001) and lack of significant toxin levels in the water and air during an unexposed period May 2002). Water samples collected during a red tide bloom in 2001 showed moderate-to-high concentrations of K. brevis cells and PbTxs. The daily mean PbTx concentration in water samples ranged from 8 to 28 μg/L from 7 to 11 September 2001; the daily mean PbTx concentration in air samples ranged from 1.3 to 27 ng/m3. The daily aerosol concentration on the beach can be related to PbTx concentration in water, wind speed, and wind direction. Personal samples confirmed human exposure to red tide aerosols. The particle size distribution showed a mean aerodynamic diameter in the size range of 6–12 μm, with deposits mainly in the upper airways. The deposition pattern correlated with the observed increase of upper airway symptoms in healthy lifeguards during the exposure periods. PMID:15866777

  15. The occupational exposure limit for fluid aerosol generated in metalworking operations: limitations and recommendations.

    PubMed

    Park, Donguk

    2012-03-01

    The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m(3), short-term exposure limit ; 15 mg/m(3)) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m(3)) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids. PMID:22953224

  16. The Occupational Exposure Limit for Fluid Aerosol Generated in Metalworking Operations: Limitations and Recommendations

    PubMed Central

    2012-01-01

    The aim of this review was to assess current knowledge related to the occupational exposure limit (OEL) for fluid aerosols including either mineral or chemical oil that are generated in metalworking operations, and to discuss whether their OEL can be appropriately used to prevent several health risks that may vary among metalworking fluid (MWF) types. The OEL (time-weighted average; 5 mg/m3, short-term exposure limit ; 15 mg/m3) has been applied to MWF aerosols without consideration of different fluid aerosol-size fractions. The OEL, is also based on the assumption that there are no significant differences in risk among fluid types, which may be contentious. Particularly, the health risks from exposure to water-soluble fluids may not have been sufficiently considered. Although adoption of The National Institute for Occupational Safety and Health's recommended exposure limit for MWF aerosol (0.5 mg/m3) would be an effective step towards minimizing and evaluating the upper respiratory irritation that may be caused by neat or diluted MWF, this would fail to address the hazards (e.g., asthma and hypersensitivity pneumonitis) caused by microbial contaminants generated only by the use of water-soluble fluids. The absence of an OEL for the water-soluble fluids used in approximately 80-90 % of all applicants may result in limitations of the protection from health risks caused by exposure to those fluids. PMID:22953224

  17. Toward Developing a New Occupational Exposure Metric Approach for Characterization of Diesel Aerosols

    PubMed Central

    Cauda, Emanuele G.; Ku, Bon Ki; Miller, Arthur L.; Barone, Teresa L.

    2015-01-01

    The extensive use of diesel-powered equipment in mines makes the exposure to diesel aerosols a serious occupational issue. The exposure metric currently used in U.S. underground noncoal mines is based on the measurement of total carbon (TC) and elemental carbon (EC) mass concentration in the air. Recent toxicological evidence suggests that the measurement of mass concentration is not sufficient to correlate ultrafine aerosol exposure with health effects. This urges the evaluation of alternative measurements. In this study, the current exposure metric and two additional metrics, the surface area and the total number concentration, were evaluated by conducting simultaneous measurements of diesel ultrafine aerosols in a laboratory setting. The results showed that the surface area and total number concentration of the particles per unit of mass varied substantially with the engine operating condition. The specific surface area (SSA) and specific number concentration (SNC) normalized with TC varied two and five times, respectively. This implies that miners, whose exposure is measured only as TC, might be exposed to an unknown variable number concentration of diesel particles and commensurate particle surface area. Taken separately, mass, surface area, and number concentration did not completely characterize the aerosols. A comprehensive assessment of diesel aerosol exposure should include all of these elements, but the use of laboratory instruments in underground mines is generally impracticable. The article proposes a new approach to solve this problem. Using SSA and SNC calculated from field-type measurements, the evaluation of additional physical properties can be obtained by using the proposed approach. PMID:26361400

  18. Determinants of exposure to metalworking fluid aerosol in small machine shops.

    PubMed

    Ross, Andrew S; Teschke, Kay; Brauer, Michael; Kennedy, Susan M

    2004-07-01

    The purpose of this study was to evaluate personal exposure to metalworking fluid (MWF) aerosols in very small machine shops (1-8 machinists per shop) and to investigate workplace factors associated with exposures. A total of 20 willing machine shops in Vancouver, Canada (from 46 eligible shops, 43%) and 88 machinists participated (participation rate for machinists 92%). Most machinists wore two personal sampling trains (an open-faced 37 mm cassette and a PM10 impactor) on each of two full work shifts. Observational data were collected regarding potential determinants of exposure at 15 min intervals throughout each shift. A total of 322 personal samples were taken over 54 days. Mean aerosol exposure was 0.32 mg/m3 (range 0.06-2.19) for the 37 mm cassette samples and 0.27 mg/m3 (range 0.026-3.67) for PM10. Exposures from the two sampler types were highly correlated (R = 0.86). The mean shop-specific ratio comparing exposure from the 37 mm cassette with that from the PM10 sampler was 1.43 and varied significantly across shops, ranging from 0.97 to 2.19. Machine, task and shop characteristics associated with significantly increased aerosol exposure included the proportion of time spent grinding, operating an enclosed computer controlled machine, the presence of welding in the shop for both sampler types and the number of machines using MWF for PM10 samples only. Factors associated with reduced aerosol exposure included machining aluminum, milling, the height (and shape) of the shop roof (for both sample types) and the presence of mechanical shop ventilation (for the 37 mm cassette samples).

  19. Prediction of Asbestos Exposure Resulting From Asbestos Aerosolization Determined Using the Releasable Asbestos Field Sampler (RAFS)

    EPA Science Inventory

    Activity-based sampling (ABS) used to evaluate breathing zone exposure to a contaminant present in soil resulting from various activities, involves breathing zone sampling for contaminants while that activity is performed. A probabilistic model based upon aerosol physics and flui...

  20. AEROSOL CONCENTRATIONS DURING THE 1999 FRESNO EXPOSURE STUDIES AS FUNCTIONS OF SIZE, SEASON, AND METEOROLOGY

    EPA Science Inventory

    The 1999 Fresno exposure studies took place in February (winter season) and April/May (spring season) for two periods of four weeks. During that time, nearly-continuous measurements of outdoor aerosol concentrations were made with a scanning mobility spectrometer (TSI SNIPS) an...

  1. In-vitro Cell Exposure Studies for the Assessment of Nanoparticle Toxicity in the Lung - A Dialogue between Aerosol Science and Biology

    SciTech Connect

    Hanns-Rudolf, Paur; Cassee, Flemming R.; Teeguarden, Justin G.; Fissan, Heinz; Diabate, Silvia; Aufderheide, M.; Kreyling, Wolfgang G.; Hanninen, Otto; Kasper, G.; Riediker, Michael; Rothen-Rutishauser, Barbara; Schmid, Otmar

    2011-10-01

    The rapid introduction of engineered nanostructured materials into numerous industrial and consumer products will result in enhanced exposure to engineered nanoparticles. Workplace exposure has been identified as the most likely source of uncontrolled inhalation of engineered aerosolized nanoparticles, but release of engineered nanoparticles may occur at any stage of the lifecycle of consumer products. The dynamic development of new nanomaterials with possibly unknown toxicological effects poses a challenge for the assessment of nanoparticle induced toxicity and safety. In this consensus document from a workshop on in-vitro cell systems for nanotoxicity testing an overview is given of the main issues concerning inhalation exposure to nanoparticles, lung physiology, nanoparticle-related biological mechanisms, in-vitro cell exposure systems for nanoparticles and social aspects of nanotechnology. The workshop participants recognized the large potential of in-vitro cell exposure systems for reliable, high-throughput screening of nanotoxicity. For the investigation of pulmonary nanotoxicity, a strong preference was expressed for air-liquid interface (ALI) cell exposure systems (rather than submerged cell exposure systems) as they closely resemble in-vivo conditions in the lungs and they allow for unaltered and dosimetrically accurate delivery of aerosolized nanoparticles to the cells. The members of the workshop believe that further advances in in-vitro cell exposure studies would be greatly facilitated by a more active role of the aerosol scientists. The technical know-how for developing and running ALI in-vitro exposure systems is available in the aerosol community and at the same time biologists/toxicologists are required for proper assessment of the biological impact of nanoparticles.

  2. Development of a Scheimpflug Lidar System for Atmospheric Aerosol Monitoring

    NASA Astrophysics Data System (ADS)

    Mei, Liang; Brydegaard, Mikkel

    2016-06-01

    This work presents a Scheimpflug lidar system which was employed for atmospheric aerosol monitoring in southern Sweden. Atmospheric aerosol fluctuation was observed around rush-hour. The extinction coefficient over 6 km was retrieved, i.e., 0.15 km-1, by employing the slop-method during the time when the atmosphere was relatively homogenous. The measurements successfully demonstrate the potential of using a Scheimpflug lidar technique for atmospheric aerosol monitoring applications.

  3. Aerosol-stable peptide-coated liposome nanoparticles: a proof-of-concept study with opioid fentanyl in enhancing analgesic effects and reducing plasma drug exposure.

    PubMed

    Hoekman, John D; Srivastava, Pramod; Ho, Rodney J Y

    2014-08-01

    Previously, we reported a novel pressurized olfactory drug (POD) delivery device that deposits aerosolized drug preferentially to upper nasal cavity. This POD device provided sustained central nervous system (CNS) levels of soluble morphine analgesic effects. However, analgesic onset of less soluble fentanyl was more rapid but brief, likely because of hydrophobic fentanyl redistribution readily back to blood. To determine whether fentanyl incorporated into an aerosol-stable liposome that binds to nasal epithelial cells will enhance CNS drug exposure and analgesic effects and reduce plasma exposure, we constructed Arg-Gly-Asp (RGD) liposomes anchored with acylated integrin-binding peptides (palmitoyl-Gly-Arg-Gly-Asp-Ser). The RGD liposomes, which assume gel phase membrane structure at 25 °C, were stable under the stress of aerosolization as only 2.2 ± 0.5% calcein leakage was detected. The RGD-mediated integrin binding of liposome is also verified to be unaffected by aerosolization. Rats treated with fentanyl in RGD liposome and POD device exhibited greater analgesic effect, as compared with the free drug counterpart (AUC(effect) = 1387.1% vs. 760.1% MPE*min), whereas approximately 20% reduced plasma drug exposure was noted (AUC(0-120) = 208.2 vs. 284.8 ng min/mL). Collectively, fentanyl incorporated in RGD liposomes is physically and biologically stable under aerosolization, enhanced the overall analgesic effects, and reduced plasma drug exposure for the first 2 h.

  4. Aerosol mass spectrometry systems and methods

    DOEpatents

    Fergenson, David P.; Gard, Eric E.

    2013-08-20

    A system according to one embodiment includes a particle accelerator that directs a succession of polydisperse aerosol particles along a predetermined particle path; multiple tracking lasers for generating beams of light across the particle path; an optical detector positioned adjacent the particle path for detecting impingement of the beams of light on individual particles; a desorption laser for generating a beam of desorbing light across the particle path about coaxial with a beam of light produced by one of the tracking lasers; and a controller, responsive to detection of a signal produced by the optical detector, that controls the desorption laser to generate the beam of desorbing light. Additional systems and methods are also disclosed.

  5. Quantitative assessment of inhalation exposure and deposited dose of aerosol from nanotechnology-based consumer sprays†

    PubMed Central

    Nazarenko, Yevgen; Lioy, Paul J.; Mainelis, Gediminas

    2015-01-01

    This study provides a quantitative assessment of inhalation exposure and deposited aerosol dose in the 14 nm to 20 μm particle size range based on the aerosol measurements conducted during realistic usage simulation of five nanotechnology-based and five regular spray products matching the nano-products by purpose of application. The products were also examined using transmission electron microscopy. In seven out of ten sprays, the highest inhalation exposure was observed for the coarse (2.5–10 μm) particles while being minimal or below the detection limit for the remaining three sprays. Nanosized aerosol particles (14–100 nm) were released, which resulted in low but measurable inhalation exposures from all of the investigated consumer sprays. Eight out of ten products produced high total deposited aerosol doses on the order of 101–103 ng kg−1 bw per application, ~85–88% of which were in the head airways, only <10% in the alveolar region and <8% in the tracheobronchial region. One nano and one regular spray produced substantially lower total deposited doses (by 2–4 orders of magnitude less), only ~52–64% of which were in the head while ~29–40% in the alveolar region. The electron microscopy data showed nanosized objects in some products not labeled as nanotechnology-based and conversely did not find nano-objects in some nano-sprays. We found no correlation between nano-object presence and abundance as per the electron microscopy data and the determined inhalation exposures and deposited doses. The findings of this study and the reported quantitative exposure data will be valuable for the manufacturers of nanotechnology-based consumer sprays to minimize inhalation exposure from their products, as well as for the regulators focusing on protecting the public health. PMID:25621175

  6. The effect of ozone exposure on the dispersion of inhaled aerosol boluses in healthy human subjects

    SciTech Connect

    Keefe, M.J.; Bennett, W.D.; DeWitt, P.; Seal, E.; Strong, A.A.; Gerrity, T.R. )

    1991-07-01

    Acute exposure of humans to low levels of ozone are known to cause decreases in FVC and increases in SRaw. These alterations in lung function do not, however, elucidate the potential for acute small airway responses. In this study we employed a test of aerosol dispersion to examine the potential effects of ozone on small airways in humans. Twenty-two healthy nonsmoking male volunteers were exposed to 0.4 ppm ozone for 1 h while exercising at 20 L/min/m2 body surface area. Before and immediately after exposure, tests of spirometry (FVC, FEV1, and FEF25-75) and plethysmography (Raw and SRaw) were performed. Subjects also performed an aerosol dispersion test before and after exposure. Each test involved a subject inhaling five to seven breaths of a 300-ml bolus of a 0.5 micron triphenyl phosphate aerosol injected into a 2-L tidal volume. The bolus was injected into the tidal breath at three different depths: at Depth A the bolus was injected after 1.6 L of clean air were inhaled from FRC, at Depth B after 1.2 L, and at Depth C after 1.2 L but with inhalation beginning from RV. The primary measure of bolus dispersion was the expired half-width (HW). Secondary measures were the ratio (expressed as percent) of peak exhaled aerosol concentration to peak inhaled concentration (PR), shift in the median bolus volume between inspiration and expiration (VS), and percent of total aerosol recovered (RC). Changes in pulmonary function after ozone exposure were consistent with previous findings.

  7. The Gillings Sampler – An Electrostatic Air Sampler as an Alternative Method for Aerosol In Vitro Exposure Studies

    PubMed Central

    Zavala, Jose; Lichtveld, Kim; Ebersviller, Seth; Carson, Johnny L.; Walters, Glenn W.; Jaspers, Ilona; Jeffries, Harvey E.; Sexton, Kenneth G.; Vizuete, William

    2014-01-01

    There is growing interest in studying the toxicity and health risk of exposure to multi-pollutant mixtures found in ambient air, and the U.S. Environmental Protection Agency (EPA) is moving towards setting standards for these types of mixtures. Additionally, the Health Effects Institute's strategic plan aims to develop and apply next-generation multi-pollutant approaches to understanding the health effects of air pollutants. There's increasing concern that conventional in vitro exposure methods are not adequate to meet EPA's strategic plan to demonstrate a direct link between air pollution and health effects. To meet the demand for new in vitro technology that better represents direct air-to-cell inhalation exposures, a new system that exposes cells at the air-liquid interface was developed. This new system, named the Gillings Sampler, is a modified two-stage electrostatic precipitator that provides a viable environment for cultured cells. Polystyrene latex spheres were used to determine deposition efficiencies (38-45%), while microscopy and imaging techniques were used to confirm uniform particle deposition. Negative control A549 cell exposures indicated the sampler can be operated for up to 4 hours without inducing any significant toxic effects on cells, as measured by lactate dehydrogenase (LDH) and interleukin-8 (IL-8). A novel positive aerosol control exposure method, consisting of a p-tolualdehyde (TOLALD) impregnated mineral oil aerosol (MOA), was developed to test this system. Exposures to the toxic MOA at a 1 ng/cm2 dose of TOLALD yielded a reproducible 1.4 and 2 fold increase in LDH and IL-8 mRNA levels over controls. This new system is intended to be used as an alternative research tool for aerosol in vitro exposure studies. While further testing and optimization is still required to produce a “commercially ready” system, it serves as a stepping-stone in the development of cost-effective in vitro technology that can be made accessible to researchers

  8. Lung cancer mortality and exposure to atmospheric aerosol particles in Guangzhou, China

    NASA Astrophysics Data System (ADS)

    Tie, Xuexi; Wu, Dui; Brasseur, Guy

    In recent years, China and other emerging countries have been experiencing severe air pollution problems with high concentrations of atmospheric aerosol particles. Satellite measurements indicate that the aerosol loading of the atmosphere in highly populated regions of China is about 10 times higher than, for example, in Europe and in the Eastern United States. The exposure to extremely high aerosol concentrations might lead to important human health effects, including respiratory and cardiovascular diseases as well as lung cancers. Here, we analyze 52-year historical surface measurements of haze data in the Chinese city of Guangzhou, and show that the dramatic increase in the occurrence of air pollution events between 1954 and 2006 has been followed by a large enhancement in the incidence of lung cancer.

  9. Dose Response of MARV/Angola Infection in Cynomolgus Macaques following IM or Aerosol Exposure

    PubMed Central

    Johnston, Sara C.; Lin, Kenny L.; Twenhafel, Nancy A.; Raymond, Jo Lynne W.; Shamblin, Joshua D.; Wollen, Suzanne E.; Wlazlowski, Carly B.; Wilkinson, Eric R.; Botto, Miriam A.; Goff, Arthur J.

    2015-01-01

    Marburg virus infection in humans causes a hemorrhagic disease with a high case fatality rate. Countermeasure development requires the use of well-characterized animal models that mimic human disease. To further characterize the cynomolgus macaque model of MARV/Angola, two independent dose response studies were performed using the intramuscular or aerosol routes of exposure. All animals succumbed at the lowest target dose; therefore, a dose effect could not be determined. For intramuscular-exposed animals, 100 PFU was the first target dose that was not significantly different than higher target doses in terms of time to disposition, clinical pathology, and histopathology. Although a significant difference was not observed between aerosol-exposed animals in the 10 PFU and 100 PFU target dose groups, 100 PFU was determined to be the lowest target dose that could be consistently obtained and accurately titrated in aerosol studies. PMID:26413900

  10. Method for chronic nose-only exposures of laboratory animals to inhaled fibrous aerosols

    SciTech Connect

    Smith, D.M.; Ortiz, L.W.; Archuleta, R.F.; Spalding, J.F.; Ettinger, H.J.; Thomas, R.G.

    1980-01-01

    A study is currently being conducted to determine any biological effects when rats and hamsters inhale man-made mineral fibers (MMMFs). The MMMF's to be tested include glass fibers, mineral wool, and ceramic fibers, with crocidolite asbestos serving as a positive control aerosol material. A prime objective of this study is to expose animals to high airborne concentrations of long thin fibers. Animal exposures are currently being conducted with a 0.45 ..mu..m mean diameter glass microfiber material and the standard UICC crocidolite. A specialized method of restraining rats and hamsters for inhalation exposure was developed providing for aerosol exposure only to the nose and a small fraction of the animal's head. This method eliminates external contamination and prevents animals from burying their noses in their fur to filter out aerosolized particles. Stainless steel chambers have been modified by placing two metal insert panels in place of doors, each containing 45 insert ports for Syrian hamsters or 32 for rats. Animals are loaded into tapered polycarbonate holding tubes and the tubes placed in the panel inserts for exposure. Body weights, rectal temperatures, clinical chemistry profiles, complete blood counts, and plasma corticosterone levels clearly indicate that this technique does not produce measurable stress in the animals.

  11. Exposure to aerosols during high-pressure cleaning and relationship with health effects.

    PubMed

    Madsen, Anne Mette; Matthiesen, Christoffer B

    2013-01-01

    In different occupations cleaning has been identified as the work task causing the highest exposure to aerosol components. High pressure cleaning (hpc) is a cleaning method used in many environments and seems to be considered as a cleaning method causing high exposure. In the presented study, the literature concerning exposure to aerosols during hpc is reviewed. Only a few studies have been published about exposure to aerosols during hpc. Exposure during hpc has been measured on farms, at waste water treatment plants, at a chemical factory and for graffiti removers. High exposures to bacterial endotoxin or chemical components were found in these environments during hpc. Few cases have been published documenting acute health effects caused by exposure to microorganisms and endotoxin during hpc. High pressure cleaners are also used in private settings but no papers have been found about exposure or related health effects during work in private settings. The use of clean water during hpc is important since effluent water or roof-collected rain water can cause a higher exposure to bioaerosols and related health effects. However, tap water in some areas also seems to have a high content of endotoxin, and this too should be considered when deliberating the protection of the airways of workers. Different attempts have been made to reduce workers' exposure and the health effects of exposure during hpc, among them the use of respiratory protection, ventilation and automation of work processes have been used with some degree of success. However, some of these studies only show tendencies. A high number of repeats seem to be necessary in order to obtain conclusive results. The material to be cleaned, as well as the degree of dirtiness, highly influences the exposure level; therefore, in comparative studies it is important also to consider these parameters. No study has been found which compares exposure during the use of different high pressure cleaners. The comparison of

  12. Exposure to aerosols during high-pressure cleaning and relationship with health effects.

    PubMed

    Madsen, Anne Mette; Matthiesen, Christoffer B

    2013-01-01

    In different occupations cleaning has been identified as the work task causing the highest exposure to aerosol components. High pressure cleaning (hpc) is a cleaning method used in many environments and seems to be considered as a cleaning method causing high exposure. In the presented study, the literature concerning exposure to aerosols during hpc is reviewed. Only a few studies have been published about exposure to aerosols during hpc. Exposure during hpc has been measured on farms, at waste water treatment plants, at a chemical factory and for graffiti removers. High exposures to bacterial endotoxin or chemical components were found in these environments during hpc. Few cases have been published documenting acute health effects caused by exposure to microorganisms and endotoxin during hpc. High pressure cleaners are also used in private settings but no papers have been found about exposure or related health effects during work in private settings. The use of clean water during hpc is important since effluent water or roof-collected rain water can cause a higher exposure to bioaerosols and related health effects. However, tap water in some areas also seems to have a high content of endotoxin, and this too should be considered when deliberating the protection of the airways of workers. Different attempts have been made to reduce workers' exposure and the health effects of exposure during hpc, among them the use of respiratory protection, ventilation and automation of work processes have been used with some degree of success. However, some of these studies only show tendencies. A high number of repeats seem to be necessary in order to obtain conclusive results. The material to be cleaned, as well as the degree of dirtiness, highly influences the exposure level; therefore, in comparative studies it is important also to consider these parameters. No study has been found which compares exposure during the use of different high pressure cleaners. The comparison of

  13. Experiences from Occupational Exposure Limits Set on Aerosols Containing Allergenic Proteins

    PubMed Central

    Nielsen, Gunnar D.

    2012-01-01

    Occupational exposure limits (OELs) together with determined airborne exposures are used in risk assessment based managements of occupational exposures to prevent occupational diseases. In most countries, OELs have only been set for few protein-containing aerosols causing IgE-mediated allergies. They comprise aerosols of flour dust, grain dust, wood dust, natural rubber latex, and the subtilisins, which are proteolytic enzymes. These aerosols show dose-dependent effects and levels have been established, where nearly all workers may be exposed without adverse health effects, which are required for setting OELs. Our aim is to analyse prerequisites for setting OELs for the allergenic protein-containing aerosols. Opposite to the key effect of toxicological reactions, two thresholds, one for the sensitization phase and one for elicitation of IgE-mediated symptoms in sensitized individuals, are used in the OEL settings. For example, this was the case for flour dust, where OELs were based on dust levels due to linearity between flour dust and its allergen levels. The critical effects for flour and grain dust OELs were different, which indicates that conclusion by analogy (read-across) must be scientifically well founded. Except for subtilisins, no OEL have been set for other industrial enzymes, where many of which are high volume chemicals. For several of these, OELs have been proposed in the scientific literature during the last two decades. It is apparent that the scientific methodology is available for setting OELs for proteins and protein-containing aerosols where the critical effect is IgE sensitization and IgE-mediated airway diseases. PMID:22843406

  14. Aerosol exposure of pigs to viable or inactivated Actinobacillus pleuropneumoniae serotype 9 induces antibodies in bronchoalveolar lining fluids and serum, and protects against homologous challenge.

    PubMed

    Hensel, A; Stockhofe-Zurwieden, N; Ganter, M; Petzoldt, K

    1995-11-01

    A dose-defined nose-only inhalation system for pigs was used to study the immunogenic and protective potentials of a single aerosol application of viable or killed Actinobacillus pleuropneumoniae serotype 9. Respiratory volumes were measured for each pig to calculate inhaled individual doses. Eight pigs inhaled 107 CFU A. pleuropneumoniae CVI 13261 reference strain for serotype 9. Another eight pigs received an identical dose of killed actinobacilli. After three weeks the pigs and nonexposed controls were challenged with 108 CFU of the homologous strain by aerosol. Bronchoalveolar lavage (BALF) in pigs was performed during the experiment to obtain lavage samples for assessment of local antibodies. Isotype-specific antibody responses in serum and BAL fluids were measured by ELISAs based on whole-cell antigens. The protective efficacy of aerosol immunization was evaluated by clinical and post-mortem examinations. The controls developed fever and severe pleuropneumonia, whereas previously exposed pigs had less fever and less extensive gross pulmonary lesions. After the first aerosol exposure pulmonary IgM, and IgG antibodies reactive with A. pleuropneumoniae increased significantly in both aerosol exposed groups. IgA in BALF and serum concentrations of each Ig class were significantly increased in the group exposed to viable bacteria when compared to the non-exposed controls. After aerosol challenge a pronounced increase of systemic and pulmonary IgA, IgM, and IgG antibodies was detected in both exposure groups. Aerosol application of whole-cell A. pleuropneumoniae bacterins induced similar protective effects against aerosol challenge infection as administration of an identical dose of viable bacteria. Inhalation of A. pleuropneumoniae may lead to asymptomatic carriers in some pigs that could spread the disease under field conditions.

  15. Recurrent aerosol antigen exposure induces distinct patterns of experimental allergic asthma in mice.

    PubMed

    Jungsuwadee, Paiboon; Dekan, Gerhard; Stingl, Georg; Epstein, Michelle M

    2002-02-01

    Patients with allergic asthma present clinically with chronic or intermittent disease caused by either persistent or periodic allergen exposure. We sought to generate clinically relevant disease in mice, which would reflect the relapsing, remitting, and constant nature of this syndrome. We generated and compared acute onset, remission, relapse, and overt phases of the disease and found that acute disease was characterized by airway hyperreactivity, eosinophilic lung inflammation, excessive mucus production, and antigen-specific antibody and was rapidly followed by a remission. Mice rechallenged with aerosol antigen during the remission or treated with repeated aerosol challenges developed relapse and overt disease, respectively. Recurrent antigen exposure induced a progressive increase in bronchoalveolar lavage fluid immunoglobulin, mucus production, and a change in inflammatory infiltrates indicating a transition from acute to chronic inflammation. These data demonstrate distinct phases of disease representing a clinical spectrum of experimental allergic asthma and may have important implications for new treatment strategies.

  16. Effect of ozone exposure on the dispersion of inhaled aerosol boluses in healthy human subjects

    SciTech Connect

    Keefe, M.J.; Bennett, W.D.; Dewitt, P.; Seal, E.; Strong, A.A.

    1990-12-06

    Acute exposure of humans to low levels of ozone are known to cause decreases FVC and increases sRaw. These alterations in lung function do not, however, elucidate the potential for acute small airways responses. In the study the authors employed a test of aerosol dispersion to examine the potential effects of ozone on small airways in humans. Twenty-two healthy non-smoking male volunteers were exposed to 0.4 ppm ozone for one hour while exercising at 20 l/min/m{sup 2} (BSA). Prior to and immediately following exposure, tests of spirometry (FVC, FEV1, and FEF25-75) and plethysmography (Raw and sRaw) were performed. Subjects also performed an aerosol dispersion test before and after exposure. Each test involved a subject inhaling five to seven breaths of a 300 ml bolus of a 0.5 micrometers triphenyl phosphate (TPP) aerosol injected into a 2 liters tidal volume. The bolus was injected into the tidal breath at three different depths: at depth A the bolus was injected after 1.6 liters of clean air was inhaled from FRC; at depth B after 1.2 liters; and at depth C after 1.2 liters but with inhalation beginning from RV. The primary measure of bolus dispersion was the expired half-width (HW).

  17. The Cloud-Aerosol Transport System (CATS): Demonstrating New Techniques for Cloud and Aerosol Measurements

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Palm, S. P.; Hlavka, D. L.; Nowottnick, E. P.; Selmer, P. A.

    2015-12-01

    The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar that provides vertical profiles of cloud and aerosol properties. The CATS payload has been operating since early February 2015 from the International Space Station (ISS). CATS was designed to operate for six months, and up to three years, providing a combination of operational science, in-space technology demonstration, and technology risk reduction for future Earth Science missions. One of the primary project goals of CATS is to demonstrate technology in support of future space-based lidar mission development. The CATS instrument has been demonstrating the high repetition rate laser and photon counting detection approach to lidar observations, in contrast to the low repetition rate, high energy technique employed by CALIPSO. Due to this technique, cloud and aerosol profile data exhibit high spatial and temporal resolution, which was never before possible from a space-based platform. Another important science goal of the CATS-FO project is accurate determination of aerosol type on a global scale. CATS provided the first space-based depolarization measurements at multiple wavelengths (532 and 1064 nm), and first measurements at 1064 nm from space. The ratio of the depolarization measurements at these two wavelengths enables significant improvement in aerosol typing. The CATS retrievals at 1064 nm also provide improvements to detecting aerosols above clouds. The CATS layer identification algorithm is a threshold-based layer detection method that uses the 1064 nm attenuated scattering ratio and also includes a routine to identify clouds embedded within aerosol layers. This technique allows CATS to detect the full extent of the aerosol layers above the cloud, and differentiate these two layers so that the optical properties can be more accurately determined.

  18. A review of in vitro cigarette smoke exposure systems.

    PubMed

    Thorne, David; Adamson, Jason

    2013-11-01

    In vitro test methods may be vital in understanding tobacco smoke, the main toxicants responsible for adverse health effects, and elucidating disease mechanisms. There is a variety of 'whole smoke' exposure systems available for the generation, dilution and delivery of tobacco smoke in vitro; these systems can be procured commercially from well-known suppliers or can be bespoke set-ups. These exposure technologies aim to ensure that there are limited changes in the tobacco smoke aerosol from generation to exposure. As the smoke aerosol is freshly generated, interactions in the smoke fractions are captured in any subsequent in vitro analysis. Of the commercially available systems, some have been characterised more than others in terms of published scientific literature and developed biological endpoints. Others are relatively new to the scientific field and are still establishing their presence. In addition, bespoke systems are widely used and offer a more flexible approach to the challenges of tobacco smoke exposure. In this review, the authors present a summary of the major tobacco smoke exposure systems available and critically review their function, set-up and application for in vitro exposure scenarios. All whole smoke exposure systems have benefits and limitations, often making it difficult to make comparisons between set-ups and the data obtained from such diverse systems. This is where exposure and dose measurements can add value and may be able to provide a platform on which comparisons can be made. The measurement of smoke dose, as an emerging field of research, is therefore also discussed and how it may provide valuable and additional data to support existing whole smoke exposure set-ups and aid validation efforts.

  19. Meteorological and Aerosol Sensing with small Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Born, J.; Möhler, O.; Haunold, W.; Schrod, J.; Brooks, I.; Norris, S.; Brooks, B.; Hill, M.; Leisner, T.

    2012-04-01

    Unmanned Aerial Systems (UAS) facilitate the monitoring of several meteorological and aerosol parameters with high resolution in space and time. They are small, easy to operate, cost efficient and allow for flexible application during field campaigns. We present two experimental payloads for measurement of relative humidity, temperature, aerosol size distribution and the collection of aerosol samples on board the small UAS SIRIUS II. The payload modules are light weight (<1kg) and can be easily switched between two flights. All sensors can be controlled from the ground and the measured data is recorded by the autopilot together with the position data. The first module contains a sensor package for measurement of relative humidity and temperature and the Compact Lightweight Aerosol Spectrometer Prope (CLASP) for acquisition of aerosol size distributions. CLASP measures aerosol particles with diameters from 0.12μm to 9.25μm in up to 32 channels at a frequency of 10 Hz. The second module also contains a humidity and temperature sensor package and the aerosol sample collection device. The aerosol sampler collects air samples at 2 l/min onto a sample holder. After the flight the ice nuclei on the sample holder are activated in the lab and counted. In August 2012 the complete setup will be used during a measurement campaign at mount "Kleiner Feldberg" close to Frankfurt. Until then we will perform test flights and additional laboratory tests.

  20. Natural History of Aerosol Exposure with Marburg Virus in Rhesus Macaques

    PubMed Central

    Ewers, Evan C.; Pratt, William D.; Twenhafel, Nancy A.; Shamblin, Joshua; Donnelly, Ginger; Esham, Heather; Wlazlowski, Carly; Johnson, Joshua C.; Botto, Miriam; Hensley, Lisa E.; Goff, Arthur J.

    2016-01-01

    Marburg virus causes severe and often lethal viral disease in humans, and there are currently no Food and Drug Administration (FDA) approved medical countermeasures. The sporadic occurrence of Marburg outbreaks does not allow for evaluation of countermeasures in humans, so therapeutic and vaccine candidates can only be approved through the FDA animal rule—a mechanism requiring well-characterized animal models in which efficacy would be evaluated. Here, we describe a natural history study where rhesus macaques were surgically implanted with telemetry devices and central venous catheters prior to aerosol exposure with Marburg-Angola virus, enabling continuous physiologic monitoring and blood sampling without anesthesia. After a three to four day incubation period, all animals developed fever, viremia, and lymphopenia before developing tachycardia, tachypnea, elevated liver enzymes, decreased liver function, azotemia, elevated D-dimer levels and elevated pro-inflammatory cytokines suggesting a systemic inflammatory response with organ failure. The final, terminal period began with the onset of sustained hypotension, dehydration progressed with signs of major organ hypoperfusion (hyperlactatemia, acute kidney injury, hypothermia), and ended with euthanasia or death. The most significant pathologic findings were marked infection of the respiratory lymphoid tissue with destruction of the tracheobronchial and mediastinal lymph nodes, and severe diffuse infection in the liver, and splenitis. PMID:27043611

  1. Natural History of Aerosol Exposure with Marburg Virus in Rhesus Macaques.

    PubMed

    Ewers, Evan C; Pratt, William D; Twenhafel, Nancy A; Shamblin, Joshua; Donnelly, Ginger; Esham, Heather; Wlazlowski, Carly; Johnson, Joshua C; Botto, Miriam; Hensley, Lisa E; Goff, Arthur J

    2016-04-01

    Marburg virus causes severe and often lethal viral disease in humans, and there are currently no Food and Drug Administration (FDA) approved medical countermeasures. The sporadic occurrence of Marburg outbreaks does not allow for evaluation of countermeasures in humans, so therapeutic and vaccine candidates can only be approved through the FDA animal rule-a mechanism requiring well-characterized animal models in which efficacy would be evaluated. Here, we describe a natural history study where rhesus macaques were surgically implanted with telemetry devices and central venous catheters prior to aerosol exposure with Marburg-Angola virus, enabling continuous physiologic monitoring and blood sampling without anesthesia. After a three to four day incubation period, all animals developed fever, viremia, and lymphopenia before developing tachycardia, tachypnea, elevated liver enzymes, decreased liver function, azotemia, elevated D-dimer levels and elevated pro-inflammatory cytokines suggesting a systemic inflammatory response with organ failure. The final, terminal period began with the onset of sustained hypotension, dehydration progressed with signs of major organ hypoperfusion (hyperlactatemia, acute kidney injury, hypothermia), and ended with euthanasia or death. The most significant pathologic findings were marked infection of the respiratory lymphoid tissue with destruction of the tracheobronchial and mediastinal lymph nodes, and severe diffuse infection in the liver, and splenitis. PMID:27043611

  2. Natural History of Aerosol Exposure with Marburg Virus in Rhesus Macaques.

    PubMed

    Ewers, Evan C; Pratt, William D; Twenhafel, Nancy A; Shamblin, Joshua; Donnelly, Ginger; Esham, Heather; Wlazlowski, Carly; Johnson, Joshua C; Botto, Miriam; Hensley, Lisa E; Goff, Arthur J

    2016-03-30

    Marburg virus causes severe and often lethal viral disease in humans, and there are currently no Food and Drug Administration (FDA) approved medical countermeasures. The sporadic occurrence of Marburg outbreaks does not allow for evaluation of countermeasures in humans, so therapeutic and vaccine candidates can only be approved through the FDA animal rule-a mechanism requiring well-characterized animal models in which efficacy would be evaluated. Here, we describe a natural history study where rhesus macaques were surgically implanted with telemetry devices and central venous catheters prior to aerosol exposure with Marburg-Angola virus, enabling continuous physiologic monitoring and blood sampling without anesthesia. After a three to four day incubation period, all animals developed fever, viremia, and lymphopenia before developing tachycardia, tachypnea, elevated liver enzymes, decreased liver function, azotemia, elevated D-dimer levels and elevated pro-inflammatory cytokines suggesting a systemic inflammatory response with organ failure. The final, terminal period began with the onset of sustained hypotension, dehydration progressed with signs of major organ hypoperfusion (hyperlactatemia, acute kidney injury, hypothermia), and ended with euthanasia or death. The most significant pathologic findings were marked infection of the respiratory lymphoid tissue with destruction of the tracheobronchial and mediastinal lymph nodes, and severe diffuse infection in the liver, and splenitis.

  3. Controlled exposures of volunteers to respirable carbon and sulfuric acid aerosols

    SciTech Connect

    Anderson, K.R.; Avol, E.L.; Edwards, S.A.; Shamoo, D.A.; Ruchuan Peng; Linn, W.S.; Hackney, J.D. )

    1992-06-01

    Respirable carbon or fly ash particles are suspected to increase the respiratory toxicity of coexisting acidic air pollutants, by concentrating acid on their surfaces and so delivering it efficiently to the lower respiratory tract. To investigate this issue, the authors exposed 15 healthy and 15 asthmatic volunteers in a controlled-environment chamber to four test atmospheres: (1) clean air; (2) 0.5-{mu}m H{sub 2}SO{sub 4} aerosol at {approx}100 {mu}g/m{sup 3}, generated from water solution; (3) 0.5-{mu}m carbon aerosol at {approx}250 {mu}g/m{sup 3}, generated from highly pure carbon black with specific surface area comparable to ambient pollution particles; and (4) carbon as in (3) plus {approx}100 {mu}g/m{sup 3} of ultrafine H{sub 2}SO{sub 4} aerosol generated from fuming sulfuric acid. Electron microscopy showed that nearly all acid in (4) became attached to carbon particle surfaces, and that most particles remained in the sub-{mu}m size range. Exposures were performed double-blind, 1 week apart. They lasted 1 hr each, with alternate 10-min periods of heavy exercise (ventilation {approx}50 L/min) and rest. Subjects gargled citrus juice before exposure to suppress airway ammonia. Lung function and symptoms were measured pre-exposure, after initial exercise, and at end-exposure. Bronchial reactivity to methacholine was measured after exposure. Statistical analyses tested for effects of H{sub 2}SO{sub 4} or carbon, separate or interactive, on health measures.

  4. Mycobacterium avium Subspecies paratuberculosis: Human Exposure through Environmental and Domestic Aerosols

    PubMed Central

    Rhodes, Glenn; Richardson, Hollian; Hermon-Taylor, John; Weightman, Andrew; Higham, Andrew; Pickup, Roger

    2014-01-01

    Mycobacterium avium subspecies paratuberculosis (Map) causes Johne’s disease in animals and is significantly associated with Crohn’s disease (CD) in humans. Our previous studies have shown Map to be present in U.K. rivers due to land deposition from chronic livestock infection and runoff driven by rainfall. The epidemiology of CD in Cardiff showed a significant association with the River Taff, in which Map can be detected on a regular basis. We have previously hypothesized that aerosols from the river might influence the epidemiology of CD. In this preliminary study, we detected Map by quantitative PCR in one of five aerosol samples collected above the River Taff. In addition, we examined domestic showers from different regions in the U.K. and detected Map in three out of 30 independent samples. In detecting Map in river aerosols and those from domestic showers, this is the first study to provide evidence that aerosols are an exposure route for Map to humans and may play a role in the epidemiology of CD. PMID:25438013

  5. Exposure of calves to aerosols of parainfluenza-3 virus and Pasteurella haemolytica.

    PubMed Central

    Carrière, P D; Maxie, M G; Wilkie, B N; Savan, M; Valli, V E; Johnson, J A

    1983-01-01

    The present study was undertaken to investigate whether sequential exposure to aerosols of parainfluenza-3 virus followed by Pasteurella haemolytica, or P. haemolytica followed by parainfluenza-3 virus, could lead to the production of pulmonary lesions in conventionally-raised calves. Twenty male calves with low serum antibody titres to both organisms were placed in five equal groups. Synergism of parainfluenza-3 virus and P. haemolytica was not demonstrated in any of the sequentially infected groups and pulmonary lesions were mild in all challenged calves. Clinical signs of disease were not present after exposure to parainfluenza-3 virus although the virus was repeatedly isolated from nasal secretions of all inoculated calves. Exposure to P. haemolytica produced a transient response which consisted of increased rectal temperatures and respiratory rates, with a mild neutrophilic leukocytosis and a mild left shift present six hours postinoculation and returning to normal within 24 hours. Results from this study suggest, although do not confirm, that reduced pulmonary clearance of inhaled P. haemolytica in parainfluenza-3 virus infected calves does not necessarily lead to production of severe pulmonary lesions and that previous exposure to aerosols of P. haemolytica may not enhance secondary parainfluenza-3 virus infection. Images Fig. 5. Fig. 6. Fig. 7. Fig. 8. Fig. 9. Fig. 10. Fig. 11. PMID:6320999

  6. Occupational Exposure to Airborne Nanomaterials: An Assessment of Worker Exposure to Aerosolized Metal Oxide Nanoparticles in Semiconductor Wastewater Treatment.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2015-01-01

    This study characterized potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolized engineered nanomaterials associated with the chemical mechanical planarization wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterization and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analyzed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone, 4 from task areas, and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100 nm-500 nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarization become aerosolized and may be accessible for inhalation exposures by workers in wastewater treatment facilities. Additional research is

  7. Occupational Exposure to Airborne Nanomaterials: An Assessment of Worker Exposure to Aerosolized Metal Oxide Nanoparticles in Semiconductor Wastewater Treatment.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2015-01-01

    This study characterized potential inhalation exposures of workers to nanometal oxides associated with industrial wastewater treatment processes in a semiconductor research and development facility. Exposure assessment methodology was designed to capture aerosolized engineered nanomaterials associated with the chemical mechanical planarization wafer polishing process that were accessible for worker contact via inhalation in the on-site wastewater treatment facility. The research team conducted air sampling using a combination of filter-based capture methods for particle identification and characterization and real-time direct-reading instruments for semi-quantitation of particle number concentration. Filter-based samples were analyzed using electron microscopy and energy-dispersive x-ray spectroscopy while real-time particle counting data underwent statistical analysis. Sampling conducted over 14 months included 5 discrete sampling series events for 7 job tasks in coordination with on-site employees. The number of filter-based samples captured for analysis by electron microscopy was: 5 from personal breathing zone, 4 from task areas, and 3 from the background. Direct-reading instruments collected data for 5 sample collection periods in the task area and the background, and 2 extended background collection periods. Engineered nanomaterials of interest (Si, Al, Ce) were identified by electron microscopy in filter-based samples from all areas of collection, existing as agglomerates (>500 nm) and nanoparticles (100 nm-500 nm). Particle counts showed an increase in number concentration during and after selected tasks above background. While additional data is needed to support further statistical analysis and determine trends, this initial investigation suggests that nanoparticles used or generated by chemical mechanical planarization become aerosolized and may be accessible for inhalation exposures by workers in wastewater treatment facilities. Additional research is

  8. Determinants of Exposure to Metalworking Fluid Aerosols: A Literature Review and Analysis of Reported Measurements

    PubMed Central

    Park, Donguk; Stewart, Patrica A.; Coble, Joseph B.

    2009-01-01

    An extensive literature review of published metalworking fluid (MWF) aerosol measurement data was conducted to identify the major determinants that may affect exposure to aerosol fractions (total or inhalable, thoracic and respirable) and mass median diameters (MMDs). The identification of determinants was conducted through published studies and analysis of published measurement levels. For the latter, weighted arithmetic means (WAMs) by number of measurements were calculated and compared using analysis of variance and t-tests. The literature review found that the major factors affecting aerosol exposure levels were, primarily, decade, type of industry, operation and fluid and engineering control measures. Our analysis of total aerosol levels found a significant decline in measured levels from an average of 5.36 mg m−3 prior to the 1970s and 2.52 mg m−3 in the 1970s to 1.21 mg m−3 in the 1980s, 0.50 mg m−3 in the 1990s and 0.55 mg m−3 in the 2000s. Significant declines from the 1990s to the 2000s also were found in thoracic fraction levels (0.48 versus 0.40 mg m−3), but not for the respirable fraction. The WAMs for the auto (1.47 mg m−3) and auto parts manufacturing industry (1.83 mg m−3) were significantly higher than that for small-job machine shops (0.68 mg m−3). In addition, a significant difference in the thoracic WAM was found between the automotive industry (0.46 mg m−3) and small-job machine shops (0.32 mg m−3). Operation type, in particular, grinding, was a significant factor affecting the total aerosol fraction [grinding operations (1.75 mg m−3) versus other machining (0.95 mg m−3)], but the levels associated with these operations were not statistically different for either the thoracic or the respirable fractions. Across all decades, the total aerosol fraction for straight oils (1.49 mg m−3) was higher than for other fluid types (soluble = 1.08 mg m−3, synthetic = 0.52 mg m−3 and semisynthetic = 0.50 mg m−3

  9. Silica exposure and systemic vasculitis.

    PubMed Central

    Mulloy, Karen B

    2003-01-01

    Work in Department of Energy (DOE) facilities has exposed workers to multiple toxic agents leading to acute and chronic diseases. Many exposures were common to numerous work sites. Exposure to crystalline silica was primarily restricted to a few facilities. I present the case of a 63-year-old male who worked in DOE facilities for 30 years as a weapons testing technician. In addition to silica, other workplace exposures included beryllium, various solvents and heavy metals, depleted uranium, and ionizing radiation. In 1989 a painful macular skin lesion was biopsied and diagnosed as leukocytoclastic vasculitis. By 1992 he developed gross hematuria and dyspnea. Blood laboratory results revealed a serum creatinine concentration of 2.1 mg/dL, ethrythrocyte sedimentation rate of 61 mm/hr, negative cANCA (antineutrophil cytoplasmic antibody cytoplasmic pattern), positive pANCA (ANCA perinuclear pattern), and antiglomerular basement membrane negative. Renal biopsy showed proliferative (crescentric) and necrotizing glomerulonephritis. The patient's diagnoses included microscopic polyangiitis, systemic necrotizing vasculitis, leukocytoclastic vasculitis, and glomerulonephritis. Environmental triggers are thought to play a role in the development of an idiopathic expression of systemic autoimmune disease. Crystalline silica exposure has been linked to rheumatoid arthritis, scleroderma, systemic lupus erythematosus, rapidly progressive glomerulonephritis and some of the small vessel vasculitides. DOE workers are currently able to apply for compensation under the federal Energy Employees Occupational Illness Compensation Program (EEOICP). However, the only diseases covered by EEOICP are cancers related to radiation exposure, chronic beryllium disease, and chronic silicosis. PMID:14644669

  10. Resuspension studies at Bikini Atoll. [Pulmonary exposure from dust-borne plutonium aerosols

    SciTech Connect

    Shinn, J.H.; Homan, D.N.; Robison, W.L.

    1980-02-01

    The following experiments were conducted on Bikini Atoll to provide key parameters for an assessment of inhalation exposure from plutonium-contaminated dust aerosols: (1) a characterization of background (plutonium activity, dust, plutonium, sea spray, and organic aerosol concentrations); (2) a study of plutonium resuspension from a bare field; (3) a study of plutonium resuspension by traffic; and (4) a study of personal inhalation exposure. Dust concentrations of 21 ..mu..g m/sup -3/ and sea spray of 34 ..mu..g m/sup -3/ were the background throughout the Bikini Island except within 50 m of the windward beach. Background concentrations of /sup 239 +240/Pu were 60 aCi m/sup -3/ in the coconut grove and 264 aCi m/sup -3/ over rain-stabilized bare soil. The ratio of plutonium activity in aerosols relative to the activity in underlying soil, defined as the enhancement factor, EF, was typically less than one. Enhancement factors increased about 3.8 as a result of tilling. Plutonium resuspension flux was estimated at 0.49 pCi m/sup -2/ year/sup -1/ over most of Bikini Island. Aerosol size distributions associated with mass and with plutonium activity were typically log-normal with median aerodynamic diameter 2.44 ..mu..m, which decreased to 2.0 ..mu..m above freshly tilled soil. The Pu concentration in aerosols collected over disturbed soil increased by a factor of 19.1. Vehicular traffic produced dust pulses typically of 10 s duration, 28 ..mu..g m/sup -3/ average concentration, and plutonium enhancement factor 2.5. Personal dosimetry showed that enhancement of dust by a worker was a factor of 2.64 for heavy work outdoors and 1.86 for light work in and around houses. Pulmonary deposition of plutonium was calculated for various exposure conditions. The pulmonary deposition ranged from 1476 aCi h/sup -1/ to 12 aCi h/sup -1/ with intermediate values for heavy outdoor work and for light work in and around houses.

  11. The Detroit Exposure and Aerosol Research Study (DEARS) - Article in National Ambient Air Quality Status and Trends through 2007

    EPA Science Inventory

    A research study that the U.S. Environmental Protection Agency conducted in Detroit, Michigan, named the Detroit Exposure and Aerosol Research Study (DEARS), will help develop data that improves our understanding of human exposure to various air pollutants in our environment.

  12. Hand calculations for transport of radioactive aerosols through sampling systems.

    PubMed

    Hogue, Mark; Thompson, Martha; Farfan, Eduardo; Hadlock, Dennis

    2014-05-01

    Workplace air monitoring programs for sampling radioactive aerosols in nuclear facilities sometimes must rely on sampling systems to move the air to a sample filter in a safe and convenient location. These systems may consist of probes, straight tubing, bends, contractions and other components. Evaluation of these systems for potential loss of radioactive aerosols is important because significant losses can occur. However, it can be very difficult to find fully described equations to model a system manually for a single particle size and even more difficult to evaluate total system efficiency for a polydispersed particle distribution. Some software methods are available, but they may not be directly applicable to the components being evaluated and they may not be completely documented or validated per current software quality assurance requirements. This paper offers a method to model radioactive aerosol transport in sampling systems that is transparent and easily updated with the most applicable models. Calculations are shown with the R Programming Language, but the method is adaptable to other scripting languages. The method has the advantage of transparency and easy verifiability. This paper shows how a set of equations from published aerosol science models may be applied to aspiration and transport efficiency of aerosols in common air sampling system components. An example application using R calculation scripts is demonstrated. The R scripts are provided as electronic attachments.

  13. Hand calculations for transport of radioactive aerosols through sampling systems.

    PubMed

    Hogue, Mark; Thompson, Martha; Farfan, Eduardo; Hadlock, Dennis

    2014-05-01

    Workplace air monitoring programs for sampling radioactive aerosols in nuclear facilities sometimes must rely on sampling systems to move the air to a sample filter in a safe and convenient location. These systems may consist of probes, straight tubing, bends, contractions and other components. Evaluation of these systems for potential loss of radioactive aerosols is important because significant losses can occur. However, it can be very difficult to find fully described equations to model a system manually for a single particle size and even more difficult to evaluate total system efficiency for a polydispersed particle distribution. Some software methods are available, but they may not be directly applicable to the components being evaluated and they may not be completely documented or validated per current software quality assurance requirements. This paper offers a method to model radioactive aerosol transport in sampling systems that is transparent and easily updated with the most applicable models. Calculations are shown with the R Programming Language, but the method is adaptable to other scripting languages. The method has the advantage of transparency and easy verifiability. This paper shows how a set of equations from published aerosol science models may be applied to aspiration and transport efficiency of aerosols in common air sampling system components. An example application using R calculation scripts is demonstrated. The R scripts are provided as electronic attachments. PMID:24667389

  14. Aerosol Sampling System for Collection of Capstone Depleted Uranium Particles in a High-Energy Environment

    SciTech Connect

    Holmes, Thomas D.; Guilmette, Raymond A.; Cheng, Yung-Sung; Parkhurst, MaryAnn; Hoover, Mark D.

    2009-03-01

    The Capstone Depleted Uranium Aerosol Study was undertaken to obtain aerosol samples resulting from a kinetic-energy cartridge with a large-caliber depleted uranium (DU) penetrator striking an Abrams or Bradley test vehicle. The sampling strategy was designed to (1) optimize the performance of the samplers and maintain their integrity in the extreme environment created during perforation of an armored vehicle by a DU penetrator, (2) collect aerosols as a function of time post-impact, and (3) obtain size-classified samples for analysis of chemical composition, particle morphology, and solubility in lung fluid. This paper describes the experimental setup and sampling methodologies used to achieve these objectives. Custom-designed arrays of sampling heads were secured to the inside of the target in locations approximating the breathing zones of the vehicle commander, loader, gunner, and driver. Each array was designed to support nine filter cassettes and nine cascade impactors mounted with quick-disconnect fittings. Shielding and sampler placement strategies were used to minimize sampler loss caused by the penetrator impact and the resulting fragments of eroded penetrator and perforated armor. A cyclone train was used to collect larger quantities of DU aerosol for chemical composition and solubility. A moving filter sample was used to obtain semicontinuous samples for depleted uranium concentration determination. Control for the air samplers was provided by five remotely located valve control and pressure monitoring units located inside and around the test vehicle. These units were connected to a computer interface chassis and controlled using a customized LabVIEW engineering computer control program. The aerosol sampling arrays and control systems for the Capstone study provided the needed aerosol samples for physicochemical analysis, and the resultant data were used for risk assessment of exposure to DU aerosol.

  15. Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme

    PubMed Central

    Toon, Owen B.; Bardeen, Charles G.; Mills, Michael J.; Fan, Tianyi; English, Jason M.; Neely, Ryan R.

    2015-01-01

    Abstract A sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties, and interactions with clouds are simulated in the size‐resolving model. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust, and sea salt. The model also includes five types of bulk secondary organic aerosols with four volatility bins. The overall cost of CESM1‐CARMA is approximately ∼2.6 times as much computer time as the standard three‐mode aerosol model in CESM1 (CESM1‐MAM3) and twice as much computer time as the seven‐mode aerosol model in CESM1 (CESM1‐MAM7) using similar gas phase chemistry codes. Aerosol spatial‐temporal distributions are simulated and compared with a large set of observations from satellites, ground‐based measurements, and airborne field campaigns. Simulated annual average aerosol optical depths are lower than MODIS/MISR satellite observations and AERONET observations by ∼32%. This difference is within the uncertainty of the satellite observations. CESM1/CARMA reproduces sulfate aerosol mass within 8%, organic aerosol mass within 20%, and black carbon aerosol mass within 50% compared with a multiyear average of the IMPROVE/EPA data over United States, but differences vary considerably at individual locations. Other data sets show similar levels of comparison with model simulations. The model suggests that in addition to sulfate, organic aerosols also significantly contribute to aerosol mass in the tropical UTLS, which is consistent with limited data.

  16. Evaluations of tropospheric aerosol properties simulated by the community earth system model with a sectional aerosol microphysics scheme

    PubMed Central

    Toon, Owen B.; Bardeen, Charles G.; Mills, Michael J.; Fan, Tianyi; English, Jason M.; Neely, Ryan R.

    2015-01-01

    Abstract A sectional aerosol model (CARMA) has been developed and coupled with the Community Earth System Model (CESM1). Aerosol microphysics, radiative properties, and interactions with clouds are simulated in the size‐resolving model. The model described here uses 20 particle size bins for each aerosol component including freshly nucleated sulfate particles, as well as mixed particles containing sulfate, primary organics, black carbon, dust, and sea salt. The model also includes five types of bulk secondary organic aerosols with four volatility bins. The overall cost of CESM1‐CARMA is approximately ∼2.6 times as much computer time as the standard three‐mode aerosol model in CESM1 (CESM1‐MAM3) and twice as much computer time as the seven‐mode aerosol model in CESM1 (CESM1‐MAM7) using similar gas phase chemistry codes. Aerosol spatial‐temporal distributions are simulated and compared with a large set of observations from satellites, ground‐based measurements, and airborne field campaigns. Simulated annual average aerosol optical depths are lower than MODIS/MISR satellite observations and AERONET observations by ∼32%. This difference is within the uncertainty of the satellite observations. CESM1/CARMA reproduces sulfate aerosol mass within 8%, organic aerosol mass within 20%, and black carbon aerosol mass within 50% compared with a multiyear average of the IMPROVE/EPA data over United States, but differences vary considerably at individual locations. Other data sets show similar levels of comparison with model simulations. The model suggests that in addition to sulfate, organic aerosols also significantly contribute to aerosol mass in the tropical UTLS, which is consistent with limited data. PMID:27668039

  17. Risk assessment of exposure to indoor aerosols associated with Chinese cooking.

    PubMed

    See, S W; Balasubramanian, R

    2006-10-01

    Cooking is an important source of indoor aerosols in residential homes and buildings with non-smokers, and thus has public health implications. However, limited information is currently available in the published literature on the physical and chemical characteristics of aerosols produced by gas cooking. Consequently, a comprehensive study was carried out to investigate the physical (number and mass concentrations and size distributions) and chemical (metals) properties in a typical Chinese food stall in Singapore where stir-frying in a wok is the most common cooking method using gas stove. To assess the contribution of cooking activities to indoor particle concentrations, aerosol measurements were performed in two distinct time periods, i.e., during cooking and non-cooking hours. The average mass concentrations of fine particles (PM(2.5)) and metals increased by a factor of 12 and 11, respectively, from 26.7 and 1.5microgm(-3) during non-cooking hours to 312.4 and 15.6microgm(-3) during cooking hours. The average number concentration was also elevated by a factor of 85, from 9.1x10(3)cm(-3) during non-cooking hours to 7.7x10(5)cm(-3) during cooking hours. Real-time particle measurements showed that about 80% of the particles associated with cooking are ultrafine particles in terms of particle counts. To evaluate the potential health threat due to inhalation of air pollutants released from gas cooking, the health risk estimates based on exposure and dose-response assessments of metals were calculated for a maximally exposed individual. The findings indicate that the indoor air quality existing at the food stall may pose adverse health effects over long-term exposure to cooking emissions.

  18. Aerosol identification using a hybrid active/passive system

    NASA Astrophysics Data System (ADS)

    D'Amico, Francis M.; Moon, Raphael P.; Davidson, Charles E.

    2005-08-01

    Recent experimental work has shown that passive systems such as hyperspectral FTIR and frequency-tunable IR cameras have application in detection of biological aerosols. This provided the motivation for a new detection technique, which we call Aerosol Ranging Spectroscopy (ARS), whereby a scattering LIDAR is used to augment passive spectrometer data to determine the location and optical depth of the aerosol plume. When the two systems are co-aligned or boresighted, the hybrid data product provides valuable enhancements for signal exploitation of the passive spectral data. This paper presents the motivation and theoretical basis for the ARS technique. A prototype implementation of an ARS system will also be described, along with preliminary results from recent outdoor field experiments.

  19. Atmospheric aerosol profiling with a bistatic imaging lidar system.

    PubMed

    Barnes, John E; Sharma, N C Parikh; Kaplan, Trevor B

    2007-05-20

    Atmospheric aerosols have been profiled using a simple, imaging, bistatic lidar system. A vertical laser beam is imaged onto a charge-coupled-device camera from the ground to the zenith with a wide-angle lens (CLidar). The altitudes are derived geometrically from the position of the camera and laser with submeter resolution near the ground. The system requires no overlap correction needed in monostatic lidar systems and needs a much smaller dynamic range. Nighttime measurements of both molecular and aerosol scattering were made at Mauna Loa Observatory. The CLidar aerosol total scatter compares very well with a nephelometer measuring at 10 m above the ground. The results build on earlier work that compared purely molecular scattered light to theory, and detail instrument improvements. PMID:17514239

  20. Reported respiratory symptom intensity in asthmatics during exposure to aerosolized Florida red tide toxins.

    PubMed

    Milian, Alexyz; Nierenberg, Kate; Fleming, Lora E; Bean, Judy A; Wanner, Adam; Reich, Andrew; Backer, Lorraine C; Jayroe, David; Kirkpatrick, Barbara

    2007-09-01

    Florida red tides are naturally occurring blooms of the marine dinoflagellate, Karenia brevis. K. brevis produces natural toxins called brevetoxins. Brevetoxins become part of the marine aerosol as the fragile, unarmored cells are broken up by wave action. Inhalation of the aerosolized toxin results in upper and lower airway irritation. Symptoms of brevetoxin inhalation include: eye, nose, and throat irritation, coughing, wheezing, chest tightness, and shortness of breath. Asthmatics appear to be more sensitive to the effects of inhaled brevetoxin. This study examined data from 97 asthmatics exposed at the beach for 1 hour during K. brevis blooms, and on separate occasions when no bloom was present. In conjunction with extensive environmental monitoring, participants were evaluated utilizing questionnaires and pulmonary function testing before and after a 1-hour beach walk. A modified Likert scale was incorporated into the questionnaire to create respiratory symptom intensity scores for each individual pre- and post-beach walk. Exposure to Florida red tide significantly increased the reported intensity of respiratory symptoms; no significant changes were seen during an unexposed period. This is the first study to examine the intensity of reported respiratory symptoms in asthmatics after a 1-hour exposure to Florida red tide.

  1. Occupational exposure to aerosolized brevetoxins during Florida red tide events: effects on a healthy worker population.

    PubMed

    Backer, Lorraine C; Kirkpatrick, Barbara; Fleming, Lora E; Cheng, Yung Sung; Pierce, Richard; Bean, Judy A; Clark, Richard; Johnson, David; Wanner, Adam; Tamer, Robert; Zhou, Yue; Baden, Daniel G

    2005-05-01

    Karenia brevis (formerly Gymnodinium breve) is a marine dinoflagellate responsible for red tides that form in the Gulf of Mexico. K. brevis produces brevetoxins, the potent toxins that cause neurotoxic shellfish poisoning. There is also limited information describing human health effects from environmental exposures to brevetoxins. Our objective was to examine the impact of inhaling aerosolized brevetoxins during red tide events on self-reported symptoms and pulmonary function. We recruited a group of 28 healthy lifeguards who are occupationally exposed to red tide toxins during their daily work-related activities. They performed spirometry tests and reported symptoms before and after their 8-hr shifts during a time when there was no red tide (unexposed period) and again when there was a red tide (exposed period). We also examined how mild exercise affected the reported symptoms and spirometry tests during unexposed and exposed periods with a subgroup of the same lifeguards. Environmental sampling (K. brevis cell concentrations in seawater and brevetoxin concentrations in seawater and air) was used to confirm unexposed/exposed status. Compared with unexposed periods, the group of lifeguards reported more upper respiratory symptoms during the exposed periods. We did not observe any impact of exposure to aerosolized brevetoxins, with or without mild exercise, on pulmonary function.

  2. Atmospheric aerosol monitoring by an elastic Scheimpflug lidar system.

    PubMed

    Mei, Liang; Brydegaard, Mikkel

    2015-11-30

    This work demonstrates a new approach - Scheimpflug lidar - for atmospheric aerosol monitoring. The atmospheric backscattering echo of a high-power continuous-wave laser diode is received by a Newtonian telescope and recorded by a tilted imaging sensor satisfying the Scheimpflug condition. The principles as well as the lidar equation are discussed in details. A Scheimpflug lidar system operating at around 808 nm is developed and employed for continuous atmospheric aerosol monitoring at daytime. Localized emission, atmospheric variation, as well as the changes of cloud height are observed from the recorded lidar signals. The extinction coefficient is retrieved according to the slope method for a homogeneous atmosphere. This work opens up new possibilities of using a compact and robust Scheimpflug lidar system for atmospheric aerosol remote sensing.

  3. Atmospheric aerosol monitoring by an elastic Scheimpflug lidar system.

    PubMed

    Mei, Liang; Brydegaard, Mikkel

    2015-11-30

    This work demonstrates a new approach - Scheimpflug lidar - for atmospheric aerosol monitoring. The atmospheric backscattering echo of a high-power continuous-wave laser diode is received by a Newtonian telescope and recorded by a tilted imaging sensor satisfying the Scheimpflug condition. The principles as well as the lidar equation are discussed in details. A Scheimpflug lidar system operating at around 808 nm is developed and employed for continuous atmospheric aerosol monitoring at daytime. Localized emission, atmospheric variation, as well as the changes of cloud height are observed from the recorded lidar signals. The extinction coefficient is retrieved according to the slope method for a homogeneous atmosphere. This work opens up new possibilities of using a compact and robust Scheimpflug lidar system for atmospheric aerosol remote sensing. PMID:26698808

  4. Differentiation of Gram-Negative Bacterial Aerosol Exposure Using Detected Markers in Bronchial-Alveolar Lavage Fluid

    PubMed Central

    Wunschel, David; Webb-Robertson, Bobbie-Jo; Frevert, Charles W.; Skerrett, Shawn; Beagley, Nat; Willse, Alan; Colburn, Heather; Antolick, Kathryn

    2009-01-01

    The identification of biosignatures of aerosol exposure to pathogens has the potential to provide useful diagnostic information. In particular, markers of exposure to different types of respiratory pathogens may yield diverse sets of markers that can be used to differentiate exposure. We examine a mouse model of aerosol exposure to known Gram negative bacterial pathogens, Francisella tularensis novicida and Pseudomonas aeruginosa. Mice were subjected to either a pathogen or control exposure and bronchial alveolar lavage fluid (BALF) was collected at four and twenty four hours post exposure. Small protein and peptide markers within the BALF were detected by matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and analyzed using both exploratory and predictive data analysis methods; principle component analysis and degree of association. The markers detected were successfully used to accurately identify the four hour exposed samples from the control samples. This report demonstrates the potential for small protein and peptide marker profiles to identify aerosol exposure in a short post-exposure time frame. PMID:19756149

  5. Differentiation of Gram-Negative Bacterial Aerosol Exposure Using Detected Markers in Bronchial-Alveolar Lavage Fluid

    SciTech Connect

    Wunschel, David S.; Webb-Robertson, Bobbie-Jo M.; Frevert, Charles W.; Skerret, Shawn J.; Beagley, Nathaniel; Willse, Alan R.; Colburn, Heather A.; Antolick, Kathryn C.

    2009-09-16

    The identification of biosignatures of aerosol exposure to pathogens has the potential to provide useful diagnostic information. In particular, markers of exposure to different types of respiratory pathogens may yield diverse sets of markers that can be used to differentiate exposure. We examine a of mouse model of aerosol exposure to known Gram negative bacterial pathogens, Francisella tularensis novicida and Pseudomonas auriginosa. Mice were subjected to either a pathogen or control exposure and bronchial alveolar lavage fluid (BALF) was collected at four and twenty four hours post exposure. Small protein and peptide markers within the BALF were detected by matrix assisted laser desorption/ionization (MALDI) mass spectrometry (MS) and analyzed using both exploratory and predictive data analysis methods; principle component analysis and degree of association. The markers detected were successfully used to accurately identify the four hour exposed samples from the control samples. This report demonstrates the potential for small protein and peptide marker profiles to identify aerosol exposure in a short post-exposure time frame.

  6. Progress and Understanding Spatial and Temporal Variability of PM2.5 and its Components in the Detroit Exposure and Aerosol Research Study (DEARS)

    EPA Science Inventory

    The Detroit Exposure and Aerosol Research Study (DEARS) measured personal exposures, ambient, residential indoor and residential outdoor concentrations of select PM2.5 aerosol components (SO4, NO3, Fe, Si, Ca, K, Mn, Pb, Zn, EC and OC) over a thr...

  7. Effects of ozone and acid aerosol exposures on surfactant-associated protein A in the lung

    SciTech Connect

    Su, W.Y.

    1993-01-01

    This study examined the effect of ozone and/or acid aerosol exposure on the level of surfactant associated protein A (SP-A), its gene expression and functionality in the lung. Guinea pigs were exposed to (1) a single exposure to 0.2 to 0.8 ppm ozone for 6 hr and sacrificed at 0 to 120 hr postexposure, (2) 0.8 ppm ozone, 6 hr/day for 3 to 5 days and sacrificed immediately postexposure, or (3) 0.8 ppm ozone, 600 [mu]g/m[sup 3] sulfuric acid, or ozone plus acid for 6 hr and sacrificed at 72 hr postexposure. The concentration of SP-A was determined by ELISA in lavage fluid, lavage cell pellets, and lung tissue compartments. SP-A gene expression was examined in lung tissue by Northern and slot blot analysis. Effect of ozone exposure on functionality of surfactant was tested by its ability to modulate phagocytic cell respiratory burst in a luminol-amplified chemiluminescence (CL) assay of phagocytic cells simulated by PMA or opsonized-zymosan. There were isolated, but significant, changes in SP-A concentrations in the lavage cell and the lavage fluid compartments at 24 and 48 hr after single exposure to 0.8 ppm ozone, respectively. Exposure to ozone and ozone plus acid also slightly increased total SP-A level in the lung. No change in SP-A gene expression was detected under the exposure conditions examined. However, surfactant from ozone exposed animals significantly enhanced CL response of phagocytic cells stimulated by either PMA or opsonized-zymosan. Blocking of the enhancement of CL by a rabbit anti-human SP-A antibody strongly suggested that SP-A may contribute in the altered respiratory burst of phagocytic cells induced by surfactant from ozone exposed animals.

  8. The Aerosol-Monsoon Climate System of Asia

    NASA Technical Reports Server (NTRS)

    Lau, William K. M.; Kyu-Myong, Kim

    2012-01-01

    In Asian monsoon countries such as China and India, human health and safety problems caused by air-pollution are worsening due to the increased loading of atmospheric pollutants stemming from rising energy demand associated with the rapid pace of industrialization and modernization. Meanwhile, uneven distribution of monsoon rain associated with flash flood or prolonged drought, has caused major loss of human lives, and damages in crop and properties with devastating societal impacts on Asian countries. Historically, air-pollution and monsoon research are treated as separate problems. However a growing number of recent studies have suggested that the two problems may be intrinsically intertwined and need to be studied jointly. Because of complexity of the dynamics of the monsoon systems, aerosol impacts on monsoons and vice versa must be studied and understood in the context of aerosol forcing in relationship to changes in fundamental driving forces of the monsoon climate system (e.g. sea surface temperature, land-sea contrast etc.) on time scales from intraseasonal variability (weeks) to climate change ( multi-decades). Indeed, because of the large contributions of aerosols to the global and regional energy balance of the atmosphere and earth surface, and possible effects of the microphysics of clouds and precipitation, a better understanding of the response to climate change in Asian monsoon regions requires that aerosols be considered as an integral component of a fully coupled aerosol-monsoon system on all time scales. In this paper, using observations and results from climate modeling, we will discuss the coherent variability of the coupled aerosol-monsoon climate system in South Asia and East Asia, including aerosol distribution and types, with respect to rainfall, moisture, winds, land-sea thermal contrast, heat sources and sink distributions in the atmosphere in seasonal, interannual to climate change time scales. We will show examples of how elevated

  9. Aerosol delivery systems for bronchial asthma.

    PubMed Central

    Ariyananda, P. L.; Agnew, J. E.; Clarke, S. W.

    1996-01-01

    Many different inhalation devices are now available for the treatment of asthma. Pressures towards the elimination of chlorofluorocarbon propellants are driving forward development of new devices-as are obvious commercial pressures, including the increased availability of generic formulations. We still, however, often cannot tell exactly where within the lung we want to target a particular medication, be it a bronchodilator or a steroid. The basic processes of aerosol deposition are readily comprehensible. Nevertheless, even under carefully supervised inhalation conditions, one can only roughly estimate where the medication is deposited. We can, however, hope to give our patients good guidance on how to make the best use of a metered-dose inhaler or a jet nebuliser. From the array of available devices, we will increasingly be able to select the most comfortable and convenient for the patient-and therefore most likely to encourage good compliance. PMID:8731705

  10. Modeling human off-site aerosol exposures to polybrominated flame retardants emitted during the land application of sewage sludge.

    PubMed

    Ziemba, Chris; Yang, Wulin; Peccia, Jordan

    2013-10-01

    Elevated sewage sludge concentrations of polybrominated diphenyl ethers (PBDEs) are due to their broad utilization in textiles and polymers, their resistance to biological degradation, and also their hydrophobic nature-which drives partitioning into wastewater solids. This study estimated the total U.S. emissions of PBDE due to sewage sludge land application and then determined the human inhalation exposure to sludge-associated PBDEs as a function meteorological conditions and downwind distances from an application site. These aerosol exposures have also been incorporated into pharmacokinetic models to predict contributions to steady-state body burden. Our results suggest that while the amount of PBDEs aerosolized during the land application process is small compared to aerosol emissions associated with product use, the application of sludges onto U.S. soils constitutes a major source of PBDEs entering the outdoor environment. Regarding aerosol exposure to nearby residents, the maximum daily inhalation dosages from a common land application scenario occur immediately after sewage sludges are applied and were 137, 27, 1.9, and 81pg/day for significant congeners PBDE-47, -99, -153 and 209 respectively. These doses are 1-2 orders of magnitude less than the standard daily inhalation exposure to the same PBDEs associated with home indoor air and are similar to doses from inhalation of urban and rural outdoor air. Under the worst-case atmospheric transport scenario, the dosages are reduced by approximately 1 order of magnitude when the setback distance between the sludge aerosolization source and human receptor is increased to 200m. Though the health implications of low-level exposures are not well-understood, these sludge-derived PBDE dosages contribute less than a tenth of 1% to the estimated total body burden of PBDE produced from inhalation of indoor and outdoor air, exposure to house dust, and exposure to PBDE from food and water intake. Overall, the inhalation of

  11. Hypersensitivity Pneumonitis-like Granulomatous Lung Disease with Nontuberculous Mycobacteria from Exposure to Hot Water Aerosols

    PubMed Central

    Sood, Akshay; Sreedhar, Rajgopal; Kulkarni, Pradeep; Nawoor, Abdur Ray

    2007-01-01

    Objective Human activities associated with aerosol-generating hot water sources are increasingly popular. Recently, a hypersensitivity pneumonitis (HP)-like granulomatous lung disease, with non-tuberculous mycobacteria from exposure to hot water aerosols from hot tubs/spas, showers, and indoor swimming pools, has been described in immunocompetent individuals (also called “hot tub lung”). Our objective in this study was to examine four additional cases of hot tub lung and compare these cases with others reported in the English print literature on this disease. Data sources and extraction We retrospectively reviewed all cases (n = 4) of presumptively diagnosed hot tub lung in immunocompetent individuals at the various physician practices in Springfield, Illinois, during 2001–2005. In addition, we searched MEDLINE for cases of hot tub lung described in the literature. Data synthesis We summarized the clinical presentation and investigations of four presumptive cases and reviewed previously reported cases of hot tub lung. Conclusions There is a debate in the literature whether hot tub lung is an HP or a direct infection of the lung by nontuberculous mycobacteria. Primary prevention of this disease relies on ventilation and good use practices. Secondary prevention of this disease requires education of both the general public and clinicians to allow for the early diagnosis of this disease. PMID:17384775

  12. Simulated consumer exposure to propellant HCFC 22 (chlorodifluoromethane) in aerosol personal products.

    PubMed

    Hartop, P J; Adams, M G

    1989-02-01

    Summary The potential human exposure to the aerosol propellant HCFC 22 (chlorodifluoromethane) arising from its use in personal products has been assessed. HCFC 22 concentrations were measured in the 'breathing zone' of an experimental manikin and an 'accompanying child' designed to simulate human use of hairsprays, body sprays and antiperspirants in a closed room. Results were expressed as the 10-min time-weighted average concentration in the air (TWA 10) and as the peak concentration in the 'breathing zone' of the 'user'. Following a 10-s use of hairspray containing approximately 20-40% HCFC 22, TWA10 values for an adult user and child were 64-116 ppm and 44-100 ppm, respectively. Use of an aerosol body spray containing 20-65% HCFC 22 for 5-20 s gave rise to TWA10 values of 32-411 ppm for an adult user and 20-395 ppm for a child. A 4-s use of an antiperspirant containing approximately 20-40% HCFC 22 sprayed at a distance of 10-30 cm from the breathing zone of the adult user generated TWA 10 values in the range of 14-34 ppm for both the adult user and child. Opening the door of the room prior to hairspray and antiperspirant spraying slightly reduced these TWA 10 values. The peak values recorded in these studies for the adult user were 208 ppm for hairspray, 1415 ppm for body sprays and 82 ppm for antiperspirants.

  13. The Aerosol Measurement and Processing System: New Capabilities and Results

    NASA Astrophysics Data System (ADS)

    Braverman, A.; Kalashnikova, O.; Manipon, G.; Paradise, S.; Penner, J.; Wilson, B.; Xing, Z.; Xu, L.

    2008-12-01

    The Aerosol Measurement and Processing System (AMAPS) is a grid based, distributed computing environment for aerosol science. AMAPS is motivated by the community's call for a modern infrastructure to access, manipulate and analyze aerosol data (see the Bulletin of the American Meteorological Society, October 2003). AMAPS offers access, subsetting, and data analysis functions for level 2 aerosol data products from MISR, MODIS, and AERONET, including the new AERONET Maritime Network. The system is available in two modes: service user mode and power user mode. Service users access data and computational capabilities through pre-constructed web pages that call workflows: web service functions chained together in XML documents. Power users access computational capabilities from the command line of AMAPS-enabled computers, by embedding web service calls directly in their python programs. The AMAPS python package also offers streamlined functions to read, extract and manipulate data over the internet. In this talk, we review the latest improvements and enhancements including the addition of the MODIS level 2 cloud product, and discuss recent science findings enabled by the AMAPS system.

  14. SPATIAL AND TEMPORAL VARIABILITY OF MOBILE SOURCE AIR TOXICS IN THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY

    EPA Science Inventory

    Data from the first two years of the Detroit Exposure and Aerosol Research Study (DEARS) were evaluated to determine spatial and temporal characteristics in concentrations of mobile source air toxics (MSATs). Outdoor concentrations of MSATs were significantly higher in samples co...

  15. Effects of 28 days silicon dioxide aerosol exposure on respiratory parameters, blood biochemical variables and lung histopathology in rats.

    PubMed

    Deb, Utsab; Lomash, Vinay; Raghuvanshi, Suchita; Pant, S C; Vijayaraghavan, R

    2012-11-01

    Inhalation toxicity of silicon dioxide aerosol (150, 300 mg/m(3)) daily over a period of 28 days was carried out in rats. The changes in respiratory variables during the period of exposure were monitored using a computer programme that recognizes the modifications of the breathing pattern. Exposure to the aerosol caused a time dependent decrease in tidal volume, with an increase in respiratory frequency compared to the control. Biochemical variables and histopathological observation were noted at 28th day following the start of exposure. Biochemical markers of silica induced lung injury like plasma alkaline phosphatase, lactate dehydrogenase and angiotensine converting enzyme activities increased in a concentration dependent manner compared to control. Increase in the plasma enzymatic activities indicates endothelial lung damage, increased lung membrane permeability. Histopathological observation of the lungs confirmed concentration dependent granulomatous inflammation, fibrosis and proteinacious degeneration. Aggregates of mononuclear cells with entrapped silica particles circumscribed by fibroblast were observed in 300 mg/m(3) silica aerosol exposed group at higher magnification. Decrease in tidal volume and increase in respiratory frequency might be due to the thickening of the alveolar wall leading to a decreased alveolar volume and lowered elasticity of the lung tissue. The trends in histological and biochemical data are in conformity with the respiratory data in the present study. This study reports for the first time, the changes in respiratory variables during silica aerosol exposure over a period of 28 days.

  16. DAILY VARIATION IN ORGANIC COMPOSITION OF FINE PARTICULATE MATTER IN THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY

    EPA Science Inventory

    Organic composition of fine particulate matter (PM2.5) was investigated as a part of the Detroit Exposure and Aerosol Research Study (DEARS). A high volume (113 liters/minute) sampler was used at the Allen Park community air monitoring station to collect PM2.5 for analysis by ga...

  17. Effects of acid aerosol exposure on the surface properties of airway mucus

    SciTech Connect

    Lee, M.M.; Schuerch, S.; Roth, S.H.

    1995-12-31

    It was hypothesized that the mucous layer lining the tracheas of rats and guinea pigs contains surfactant material capable of lowering the air/mucus surface tension, {gamma}, and that exposure to an irritant aerosol would raise the {gamma}. The {gamma} of the surface film was measured directly by a spreading droplet technique and indirectly by displacement of polymethyl methacrylate particles into the aqueous layer. The morphology of the mucous film was examined by electron microscopy after nonaqueous fixation. {gamma} was 33.3 {plus_minus} 0.70 (SE) mN/m and 32.3 {plus_minus} 0.68 (SE) mN/m for the normal rat and guinea pig trachea, respectively. Exposure for 4 h to aerosols of sulfuric acid (94.1 {plus_minus} 18.68 (SD) and 43.3 {plus_minus} 4.57 (SD) mg/m{sup 3}) caused a several-fold increase in thickness of the mucous layer with exudation of protein-like material. The osmiophilic surfactant film at the air/mucus interface became irregularly thickened and multilayered. Despite these morphological changes {gamma} remained low, 33.2 {plus_minus} 0.43 (SE) mN/m and 32.6 {plus_minus} 0.60 (SE) mN/m for rats and guinea pigs, respectively, and displacement of particles into the subphase was not compromised. The results indicate that rodent tracheas are able to maintain a low surface tension in the presence of injury. 24 refs., 9 figs.

  18. Aerosol assisted depositions of polymers using an atomiser delivery system.

    PubMed

    Crick, Colin R; Clausen-Thue, Victoria; Parkin, Ivan P

    2011-09-01

    The hydrophobicity, robustness and anti-microbial properties of Sylgard 184 polymer films deposited via AACVD were optimised by using aerosol droplets from an atomiser delivery system, polymer coating substrates and the swell encapsulation of methylene blue. By using an atomiser deposition system (average droplet size 0.35 microm) rather than a misting aerosol system (45 microm) lead to a surface with smaller surface features, which improved hydrophobicity (water contact angle 165 degrees) in addition to increasing the films transparency from ca 10 to 65%. Pre-treating the substrates with the same Sylgard 184 elastomer lead to a highly consistent surface hydrophobicity and an increase in average water contact angle measured (169 degrees). This paper shows the first example of dye incorporation in a CVD derived polymer film-these films have potential as antimicrobial surfaces. PMID:22097584

  19. Aerosol assisted depositions of polymers using an atomiser delivery system.

    PubMed

    Crick, Colin R; Clausen-Thue, Victoria; Parkin, Ivan P

    2011-09-01

    The hydrophobicity, robustness and anti-microbial properties of Sylgard 184 polymer films deposited via AACVD were optimised by using aerosol droplets from an atomiser delivery system, polymer coating substrates and the swell encapsulation of methylene blue. By using an atomiser deposition system (average droplet size 0.35 microm) rather than a misting aerosol system (45 microm) lead to a surface with smaller surface features, which improved hydrophobicity (water contact angle 165 degrees) in addition to increasing the films transparency from ca 10 to 65%. Pre-treating the substrates with the same Sylgard 184 elastomer lead to a highly consistent surface hydrophobicity and an increase in average water contact angle measured (169 degrees). This paper shows the first example of dye incorporation in a CVD derived polymer film-these films have potential as antimicrobial surfaces.

  20. Alveolar targeting of aerosol pentamidine. Toward a rational delivery system

    SciTech Connect

    Simonds, A.K.; Newman, S.P.; Johnson, M.A.; Talaee, N.; Lee, C.A.; Clarke, S.W. )

    1990-04-01

    Nebulizer systems that deposit a high proportion of aerosolized pentamidine on large airways are likely to be associated with marked adverse side effects, which may lead to premature cessation of treatment. We have measured alveolar deposition and large airway-related side effects (e.g., cough, breathlessness, and effect on pulmonary function) after aerosolization of 150 mg pentamidine isethionate labeled with {sup 99m}Tc-Sn-colloid. Nine patients with AIDS were studied using three nebulizer systems producing different droplet size profiles: the Acorn System 22, Respirgard II, and Respirgard II with the inspiratory baffle removed. Alveolar deposition was greatest and side effects least with the nebulizer producing the smallest droplet size profile (Respirgard II), whereas large airway-related side effects were prominent and alveolar deposition lowest with the nebulizer producing the largest droplet size (Acorn System 22). Values for alveolar deposition and adverse airway effects were intermediate using the Respirgard with inspiratory baffle removed, thus indicating the importance of the baffle valve in determining droplet size. Addition of a similar baffle valve to the Acorn System 22 produced a marked improvement in droplet size profile. Selection of a nebulizer that produces an optimal droplet size range offers the advantage of enhancing alveolar targeting of aerosolized pentamidine while reducing large airway-related side effects.

  1. Aerosol exposure to Rift Valley fever virus causes earlier and more severe neuropathology in the murine model, which has important implications for therapeutic development.

    PubMed

    Reed, Christopher; Lin, Kenny; Wilhelmsen, Catherine; Friedrich, Brian; Nalca, Aysegul; Keeney, Ashley; Donnelly, Ginger; Shamblin, Joshua; Hensley, Lisa E; Olinger, Gene; Smith, Darci R

    2013-01-01

    Rift Valley fever virus (RVFV) is an important mosquito-borne veterinary and human pathogen that can cause severe disease including acute-onset hepatitis, delayed-onset encephalitis, retinitis and blindness, or a hemorrhagic syndrome. Currently, no licensed vaccine or therapeutics exist to treat this potentially deadly disease. Detailed studies describing the pathogenesis of RVFV following aerosol exposure have not been completed and candidate therapeutics have not been evaluated following an aerosol exposure. These studies are important because while mosquito transmission is the primary means for human infection, it can also be transmitted by aerosol or through mucosal contact. Therefore, we directly compared the pathogenesis of RVFV following aerosol exposure to a subcutaneous (SC) exposure in the murine model by analyzing survival, clinical observations, blood chemistry, hematology, immunohistochemistry, and virus titration of tissues. Additionally, we evaluated the effectiveness of the nucleoside analog ribavirin administered prophylactically to treat mice exposed by aerosol and SC. The route of exposure did not significantly affect the survival, chemistry or hematology results of the mice. Acute hepatitis occurred despite the route of exposure. However, the development of neuropathology occurred much earlier and was more severe in mice exposed by aerosol compared to SC exposed mice. Mice treated with ribavirin and exposed SC were partially protected, whereas treated mice exposed by aerosol were not protected. Early and aggressive viral invasion of brain tissues following aerosol exposure likely played an important role in ribavirin's failure to prevent mortality among these animals. Our results highlight the need for more candidate antivirals to treat RVFV infection, especially in the case of a potential aerosol exposure. Additionally, our study provides an account of the key pathogenetic differences in RVF disease following two potential exposure routes and

  2. Adapting Concepts from Systems Biology to Develop Systems Exposure Event Networks for Exposure Science Research

    EPA Science Inventory

    Systems exposure science has emerged from the traditional environmental exposure assessment framework and incorporates new concepts that link sources of human exposure to internal dose and metabolic processes. Because many human environmental studies are designed for retrospectiv...

  3. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems.

    PubMed

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit

    2016-08-15

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0-9.7×10(4)CFUm(-2)h(-1)) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate

  4. Quantification and risks associated with bacterial aerosols near domestic greywater-treatment systems.

    PubMed

    Benami, Maya; Busgang, Allison; Gillor, Osnat; Gross, Amit

    2016-08-15

    Greywater (GW) reuse can alleviate water stress by lowering freshwater consumption. However, GW contains pathogens that may compromise public health. During the GW-treatment process, bioaerosols can be produced and may be hazardous to human health if inhaled, ingested, or come in contact with skin. Using air-particle monitoring, BioSampler®, and settle plates we sampled bioaerosols emitted from recirculating vertical flow constructed wetlands (RVFCW) - a domestic GW-treatment system. An array of pathogens and indicators were monitored using settle plates and by culturing the BioSampler® liquid. Further enumeration of viable pathogens in the BioSampler® liquid utilized a newer method combining the benefits of enrichment with molecular detection (MPN-qPCR). Additionally, quantitative microbial risk assessment (QMRA) was applied to assess risks of infection from a representative skin pathogen, Staphylococcus aureus. According to the settle-plate technique, low amounts (0-9.7×10(4)CFUm(-2)h(-1)) of heterotrophic bacteria, Staphylococcus spp., Pseudomonas spp., Klebsiella pneumoniae, Enterococcus spp., and Escherichia coli were found to aerosolize up to 1m away from the GW systems. At the 5m distance amounts of these bacteria were not statistically different (p>0.05) from background concentrations tested over 50m away from the systems. Using the BioSampler®, no bacteria were detected before enrichment of the GW-aerosols. However, after enrichment, using an MPN-qPCR technique, viable indicators and pathogens were occasionally detected. Consequently, the QMRA results were below the critical disability-adjusted life year (DALY) safety limits, a measure of overall disease burden, for S. aureus under the tested exposure scenarios. Our study suggests that health risks from aerosolizing pathogens near RVFCW GW-treatment systems are likely low. This study also emphasizes the growing need for standardization of bioaerosol-evaluation techniques to provide more accurate

  5. NIOSH field studies team assessment: Worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fabrication facility.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Eastlake, Adrienne C; Beaucham, Catherine C; Geraci, Charles L

    2016-11-01

    The ubiquitous use of engineered nanomaterials-particulate materials measuring approximately 1-100 nanometers (nm) on their smallest axis, intentionally engineered to express novel properties-in semiconductor fabrication poses unique issues for protecting worker health and safety. Use of new substances or substances in a new form may present hazards that have yet to be characterized for their acute or chronic health effects. Uncharacterized or emerging occupational health hazards may exist when there is insufficient validated hazard data available to make a decision on potential hazard and risk to exposed workers under condition of use. To advance the knowledge of potential worker exposure to engineered nanomaterials, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted an on-site field evaluation in collaboration with on-site researchers at a semiconductor research and development facility on April 18-21, 2011. The Nanomaterial Exposure Assessment Technique (2.0) was used to perform a complete exposure assessment. A combination of filter-based sampling and direct-reading instruments was used to identify, characterize, and quantify the potential for worker inhalation exposure to airborne alumina and amorphous silica nanoparticles associated with th e chemical mechanical planarization wafer polishing process. Engineering controls and work practices were evaluated to characterize tasks that might contribute to potential exposures and to assess existing engineering controls. Metal oxide structures were identified in all sampling areas, as individual nanoparticles and agglomerates ranging in size from 60 nm to >1,000 nm, with varying structure morphology, from long and narrow to compact. Filter-based samples indicated very little aerosolized material in task areas or worker breathing zone. Direct-reading instrument data indicated increased particle counts relative to background in the wastewater treatment area; however

  6. NIOSH field studies team assessment: Worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fabrication facility.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Eastlake, Adrienne C; Beaucham, Catherine C; Geraci, Charles L

    2016-11-01

    The ubiquitous use of engineered nanomaterials-particulate materials measuring approximately 1-100 nanometers (nm) on their smallest axis, intentionally engineered to express novel properties-in semiconductor fabrication poses unique issues for protecting worker health and safety. Use of new substances or substances in a new form may present hazards that have yet to be characterized for their acute or chronic health effects. Uncharacterized or emerging occupational health hazards may exist when there is insufficient validated hazard data available to make a decision on potential hazard and risk to exposed workers under condition of use. To advance the knowledge of potential worker exposure to engineered nanomaterials, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted an on-site field evaluation in collaboration with on-site researchers at a semiconductor research and development facility on April 18-21, 2011. The Nanomaterial Exposure Assessment Technique (2.0) was used to perform a complete exposure assessment. A combination of filter-based sampling and direct-reading instruments was used to identify, characterize, and quantify the potential for worker inhalation exposure to airborne alumina and amorphous silica nanoparticles associated with th e chemical mechanical planarization wafer polishing process. Engineering controls and work practices were evaluated to characterize tasks that might contribute to potential exposures and to assess existing engineering controls. Metal oxide structures were identified in all sampling areas, as individual nanoparticles and agglomerates ranging in size from 60 nm to >1,000 nm, with varying structure morphology, from long and narrow to compact. Filter-based samples indicated very little aerosolized material in task areas or worker breathing zone. Direct-reading instrument data indicated increased particle counts relative to background in the wastewater treatment area; however

  7. NIOSH Field Studies Team Assessment: Worker Exposure to Aerosolized Metal Oxide Nanoparticles in a Semiconductor Fabrication Facility

    PubMed Central

    Brenner, Sara A.; Neu-Baker, Nicole M.; Eastlake, Adrienne C.; Beaucham, Catherine C.; Geraci, Charles L.

    2016-01-01

    The ubiquitous use of engineered nanomaterials – particulate materials measuring approximately 1–100 nanometers (nm) on their smallest axis, intentionally engineered to express novel properties – in semiconductor fabrication poses unique issues for protecting worker health and safety. Use of new substances or substances in a new form may present hazards that have yet to be characterized for their acute or chronic health effects. Uncharacterized or emerging occupational health hazards may exist when there is insufficient validated hazard data available to make a decision on potential hazard and risk to exposed workers under condition of use. To advance the knowledge of potential worker exposure to engineered nanomaterials, the National Institute for Occupational Safety and Health Nanotechnology Field Studies Team conducted an on-site field evaluation in collaboration with on-site researchers at a semiconductor research and development facility on April 18–21, 2011. The Nanomaterial Exposure Assessment Technique (2.0) was used to perform a complete exposure assessment. A combination of filter-based sampling and direct-reading instruments was used to identify, characterize, and quantify the potential for worker inhalation exposure to airborne alumina and amorphous silica nanoparticles associated with the chemical mechanical planarization wafer polishing process. Engineering controls and work practices were evaluated to characterize tasks that might contribute to potential exposures and to assess existing engineering controls. Metal oxide structures were identified in all sampling areas, as individual nanoparticles and agglomerates ranging in size from 60nm to >1,000nm, with varying structure morphology, from long and narrow to compact. Filter-based samples indicated very little aerosolized material in task areas or worker breathing zone. Direct-reading instrument data indicated increased particle counts relative to background in the wastewater treatment area

  8. A novel aerosol-mediated drug delivery system for inner ear therapy: intratympanic aerosol methylprednisolone can attenuate acoustic trauma.

    PubMed

    Li, Ming-Lung; Lee, Lung-Cheng; Cheng, Yuh-Ren; Kuo, Ching-Hua; Chou, Yuan-Fang; Chen, Yuh-Shyang; Yao, Chih-Min; Chen, Peir-Rong; Hsu, Chuan-Jen; Song, Yu-Lin; Lee, Chia-Fone

    2013-09-01

    We developed a novel aerosol-mediated drug delivery system for inner ear therapy by using a silicon-based multiple-Fourier horn nozzle. Intratympanic aerosol (ITA) methylprednisolone (MP) delivery can protect hearing after acoustic trauma. The highest concentration of MP (38.9 ± 5.47 ppm) appeared at 2 h and declined rapidly within 10 h. The concentrations of MP remained at a relatively low level for more than 10 h. Compared to the baseline, the auditory brainstem response (ABR) thresholds shifted markedly at 1 h after noise exposure in all groups (p < 0.05). From the cochleograms, it can be noted that the main lesions encompassed the 2-20 kHz frequency range. Significant differences ( ) were observed for the range between 5 and 8 kHz in the cell loss of outer hair cells (OHCs). The losses for IHCs were lower than for OHCs. The MP movement in the middle ear was simulated by a convection diffusion equation with a relaxation time. The relaxation time was 0.5 h, and the concentration threshold of MP on the round window membrane (RWM) in the middle ear (C T) was 8900 ppm. Using the unit hydrograph (UH) method, we obtained a proper boundary concentration on the RWM at the cochlea, which resulted in a well-fit concentration. Finally, a linking mechanism between the middle ear and the cochlea was established by the RWM. The adjustable permeability and concentration threshold provide the flexibility to match the peak times and peak values of the concentration on the RWM in the middle ear and the cochlea.

  9. Utility of MODIS Aerosol Optical Depth for Estimating PM2.5 Exposure in Environmental Public Health Surveillance

    NASA Technical Reports Server (NTRS)

    Al-Hamdan, Mohammad; Crosson, William; Limaye, Ashutosh; Rickman, Doug; Quattrochi, Dale; Estes, Maury; Adeniyi, Kafayat; Qualters, Judith; Niskar, Amanda Sue

    2006-01-01

    , including PM(2.5). Thus, HELIX-Atlanta is focusing on methods for characterizing population exposure to PM(2.5) for the Atlanta metropolitan area that could be used in on-going surveillance. While use of the Air Quality System, (AQS) PM(2.5) data alone could meet HELIX Atlanta, specifications, there are only five AQS sites in the Atlanta area, thus the spatial coverage is not ideal. Also, the AQS ground observations are made at time intervals ranging from one hour to six days leaving some temporal gaps. NASA Moderate Resolution Imaging Spectroradiometer (MODIS) satellite Aerosol Optical Depth (AOD) data have the potential for estimating daily ground level PM(2.5) at 10 km resolution over the metropolitan Atlanta area supplementing the AQS ground observations and filling their spatial and temporal gaps.

  10. Short inhalation exposures of the isolated and perfused rat lung to respirable dry particle aerosols; the detailed pharmacokinetics of budesonide, formoterol, and terbutaline.

    PubMed

    Ewing, Per; Eirefelt, Stefan J; Andersson, Paul; Blomgren, Anders; Ryrfeldt, Ake; Gerde, Per

    2008-06-01

    There is an increasing interest in using the lung as a route of entry for both local and systemic administration of drugs. However, because adequate technologies have been missing in the preclinical setting, few investigators have addressed the detailed disposition of drugs in the lung following short inhalation exposures to highly concentrated dry powder aerosols. New methods are needed to explore the disposition of drugs after short inhalation exposures, thus mimicking a future clinical use. Our aim was to study the pulmonary disposition of budesonide, formoterol, and terbutaline, which are clinically used for the treatment of bronchial asthma. Using the recently developed DustGun aerosol technology, we exposed by inhalation for approximately 1 min the isolated and perfused rat lung (IPL) to respirable dry particle aerosols of the three drugs at high concentrations. The typical aerosol concentration was 1 mug/mL, and the particle size distribution of the tested substances varied with a MMAD ranging from 2.3 to 5.3 mum. The IPL was perfused in single pass mode and repeated samples of the perfusate were taken for up to 80 min postexposure. The concentration of drug in perfusate and in lung extracts was measured using LC-MS/MS. The deposited dose was determined by adding the amounts of drug collected in perfusate to the amount extracted from the tissues at 80 min. Deposited amounts of budesonide, formoterol fumarate, and terbutaline sulphate were 23 +/- 17, 36 +/- 8, and 60 +/- 3.2 mug (mean +/- SD, n = 3), respectively. Retention in lung tissues at the end of the perfusion period expressed as fraction of deposited dose was 0.19 +/- 0.05, 0.19 +/- 0.06, and 0.04 +/- 0.01 (mean +/- SD, n = 3) for budesonide, formoterol, and terbutaline, respectively. Each short inhalation exposure to the highly concentrated aerosols consumed 1-3 mg powder. Hence, this system can be particularly useful for obtaining a detailed pharmacokinetic characterization of inhaled compounds in

  11. Lessons learned from case studies of inhalation exposures of workers to radioactive aerosols

    SciTech Connect

    Hoover, M.D.; Fencl, A.F.; Newton, G.J.

    1995-12-01

    Various Department of Energy requirements, rules, and orders mandate that lessons learned be identified, evaluated, shared, and incorporated into current practices. The recently issued, nonmandatory DOE standard for Development of DOE Lessons Learned Program states that a DOE-wide lessons learned program will {open_quotes}help to prevent recurrences of negative experiences, highlight best practices, and spotlight innovative ways to solve problems or perform work more safely, efficiently, and cost effectively.{close_quotes} Additional information about the lessons learned program is contained in the recently issued DOE handbook on Implementing U.S. Department of Energy Lessons Learned Programs and in October 1995 DOE SAfety Notice on Lessons Learned Programs. This report summarizes work in progress at ITRI to identify lessons learned for worker exposures to radioactive aerosols, and describes how this work will be incorporated into the DOE lessons learned program, including a new technical guide for measuring, modeling, and mitigating airborne radioactive particles. Follow-on work is focusing on preparation of {open_quotes}lessons learned{close_quotes} training materials for facility designers, managers, health protection professionals, line supervisors, and workers.

  12. Evaluation of toxicity to triclosan in rats following 28 days of exposure to aerosol inhalation.

    PubMed

    Yang, Young-Su; Kwon, Jung-Taek; Shim, Ilseob; Kim, Hyun-Mi; Kim, Pilje; Kim, Jong-Choon; Lee, Kyuhong

    2015-03-01

    The present study was conducted to investigate the potential subchronic toxicity of triclosan (TCS) in rats following 28 days of exposure by repeated inhalation. Four groups of six rats of each sex were exposed to TCS-containing aerosols by nose-only inhalation of 0, 0.04, 0.13, or 0.40 mg/L for 6 h/day, 5 days/week over a 28-day period. During the study period, clinical signs, mortality, body weight, food consumption, ophthalmoscopy, hematology, serum biochemistry, gross pathology, organ weights, and histopathology were examined. At 0.40 mg/L, rats of both sexes exhibited an increase in the incidence of postdosing salivation and a decrease in body weight. Histopathological alterations were found in the nasal septum and larynx. There were no treatment-related effects in rats of either sex at ⩽0.13 mg/L. Under the present experimental conditions, the target organs in rats were determined to be the nasal cavity and larynx. The no-observed-adverse-effect concentration in rats was determined to be 0.13 mg/L.

  13. Workers’ cytokines profiling upon exposure to MWCNT aerosol in occupational settings

    NASA Astrophysics Data System (ADS)

    Fatkhutdinova, L. M.; Khaliullin, T. O.; Zalyalov, R. R.; Vasilyeva, O. L.; Valeeva, I. Kh; Mustafin, I. G.

    2015-11-01

    Recent studies have found that upon pulmonary exposure to multi-walled carbon nanotubes (MWCNTs) animals develop primarily fibrosis and granulomas in lungs. In vitro and in vivo studies also give reason to assume that local exposure could be related to remote effects, including immune system and the endothelium. To investigate the remote effect hypothesis, we have analyzed blood, nasal lavage and induced sputum samples taken from workers in the frame of the Russian epidemiological study on Carbon Nanotubes Exposure and Risk Assessment (CNT-ERA). In serum and nasal lavage no significant differences between exposure and control groups were observed with a high variability to the cytokines content. In the samples of induced sputum from exposed workers the content of IL-1b, IL-6, IL-8, TNF-a, IL-4, IL-5, IFN-g exceeded the control group values, but after the regression models construction and bootstrap analysis, significant differences were found only for IL-1b. This study could not provide evidences of blood cytokines changes following local cytokine production in airways in workers exposed to MWCNTs. Cytokines variability in serum and nasal lavage may indicate the absence of severe systemic inflammatory response upon the existing occupational exposure to MWCNTs. Other systemic responses (including allergy-like or autoimmune reactions) should be regarded as well.

  14. Measurements of Atmospheric Aerosol Vertical Distributions above Svalbard, Norway using Unmanned Aerial Systems (UAS)

    NASA Astrophysics Data System (ADS)

    Bates, T. S.; Johnson, J. E.; Stalin, S.; Telg, H.; Murphy, D. M.; Burkhart, J. F.; Quinn, P.; Storvold, R.

    2015-12-01

    Atmospheric aerosol vertical distributions were measured above Svalbard, Norway in April 2015 to investigate the processes controlling aerosol concentrations and radiative effects. The aerosol payload was flown in a NOAA/PMEL MANTA Unmanned Aerial System (UAS) on 9 flights totaling 19 flight hours. Measurements were made of particle number concentration and aerosol light absorption at three wavelengths, similar to those conducted in April 2011 (Bates et al., Atmos. Meas. Tech., 6, 2115-2120, 2013). A filter sample was collected on each flight for analyses of trace elements. Additional measurements in the aerosol payload in 2015 included aerosol size distributions obtained using a Printed Optical Particle Spectrometer (POPS) and aerosol optical depth obtained using a four wavelength miniature Scanning Aerosol Sun Photometer (miniSASP). The data show most of the column aerosol mass and resulting optical depth in the boundary layer but frequent aerosol layers aloft with high particle number concentration (2000 cm-3) and enhanced aerosol light absorption (1 Mm-1). Transport of these aerosol layers was assessed using FLEXPART particle dispersion models. The data contribute to an assessment of sources of BC to the Arctic and potential climate impacts.

  15. Effects of aerosol on evaporation, freezing and precipitation in a multiple cloud system

    NASA Astrophysics Data System (ADS)

    Lee, Seoung Soo; Kim, Byung-Gon; Yum, Seong Soo; Seo, Kyong-Hwan; Jung, Chang-Hoon; Um, Jun Shik; Li, Zhanqing; Hong, JinKyu; Chang, Ki-Ho; Jeong, Jin-Yim

    2016-04-01

    Aerosol effects on clouds and precipitation account for a large portion of uncertainties in the prediction of the future course of global hydrologic circulations and climate. As a process of a better understanding of interactions between aerosol, clouds and precipitation, simulations are performed for a mixed-phase convective multiple-cloud system over the tropics. Studies on single-cloud systems have shown that aerosol-induced increases in freezing, associated increases in parcel buoyancy and thus the intensity of clouds (or updrafts) are a main mechanism which controls aerosol-cloud-precipitation interactions in convective clouds. However, in the multiple-cloud system that plays much more important roles in global hydrologic circulations and thus climate than single-cloud systems, aerosol effects on condensation play the most important role in aerosol-induced changes in the intensity of clouds and the effects on freezing play a negligible role in those changes. Aerosol-induced enhancement in evaporation intensifies gust fronts and increases the number of subsequently developing clouds, which leads to the substantial increases in condensation and associated intensity of convection. Although aerosol-induced enhancement in freezing takes part in the increases in condensation by inducing stronger convergence around cloud bottom, the increases in condensation are ~one order of magnitude larger than those in freezing. It is found that while aerosol-induced increases in freezing create intermittent extremely heavy precipitation, aerosol-induced increases in evaporation enhance light and medium precipitation in the multiple-cloud system here. This increase in light and medium precipitation makes it possible that cumulative precipitation increases with increasing aerosol concentration, although the increase is small. It is interesting that the altitude of the maximum of the time- and domain-averaged hydrometeor mass densities is quite robust to increases in aerosol

  16. Untangling aerosol effects on clouds and precipitation in a buffered system.

    PubMed

    Stevens, Bjorn; Feingold, Graham

    2009-10-01

    It is thought that changes in the concentration of cloud-active aerosol can alter the precipitation efficiency of clouds, thereby changing cloud amount and, hence, the radiative forcing of the climate system. Despite decades of research, it has proved frustratingly difficult to establish climatically meaningful relationships among the aerosol, clouds and precipitation. As a result, the climatic effect of the aerosol remains controversial. We propose that the difficulty in untangling relationships among the aerosol, clouds and precipitation reflects the inadequacy of existing tools and methodologies and a failure to account for processes that buffer cloud and precipitation responses to aerosol perturbations.

  17. Effect of oxidant concentration, exposure time, and seed particles on secondary organic aerosol chemical composition and yield

    DOE PAGES

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; et al

    2015-03-18

    We performed a systematic intercomparison study of the chemistry and yields of secondary organic aerosol (SOA) generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0 × 108 to 2.2 × 1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2 × 106 to 2 × 107 molec cm-3 over exposure times of several hours. The OH concentration in themore » chamber experiments is close to that found in the atmosphere, but the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. In most cases, for a specific SOA type the most-oxidized chamber SOA and the least-oxidized flow reactor SOA have similar mass spectra, oxygen-to-carbon and hydrogen-to-carbon ratios, and carbon oxidation states at integrated OH exposures between approximately 1 × 1011 and 2 × 1011 molec cm-3 s, or about 1–2 days of equivalent atmospheric oxidation. This observation suggests that in the range of available OH exposure overlap for the flow reactor and chambers, SOA elemental composition as measured by an aerosol mass spectrometer is similar whether the precursor is exposed to low OH concentrations over long exposure times or high OH concentrations over short exposure times. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of

  18. Aerosol observing system platform integration and AAF instrumentation

    SciTech Connect

    Springston, S.; Sedlacek, A.

    2010-03-15

    As part of the federal government’s 2009 American Recovery and Reinvestment Act (ARRA), the U.S. DOE Office of Science allocated funds for the capital upgrade of the Atmospheric Radiation Measurement (ARM) Climate Research Facility to improve and expand observational capabilities related to cloud and aerosol properties. The ARM Facility was established as a national user facility for the global scientific community to conduct a wide range of interdisciplinary science. Part of the ARRA-funded expansion of the ARM Facility includes four new Aerosol Observing Systems (AOS) to be designed, instrumented, and mentored by BNL. The enclosures will be customized SeaTainers. These new platforms ([AMF2]: ARM Mobile Facility-2; [TWP-D]: Tropical Western Pacific at Darwin; and [MAOS-A]/[MAOS-C]: Mobile Aerosol Observing System-Aerosol/-Chemistry) will provide a laboratory environment for fielding instruments to collect data on aerosol life cycle, microphysics, and optical/physical properties. The extensive instrument suite includes both established methods and initial deployments of new techniques to add breadth and depth to the AOS data sets. The platforms are designed: (1) to have all instruments pre-installed before deployment, allowing a higher measurement duty cycle; (2) with a standardized configuration improving the robustness of data inter-comparability; (3) to provide remote access capability for instrument mentors; and (4) to readily accommodate guest instrumentation. The first deployment of the AMF2 platform will be at the upcoming StormVEx campaign held at Steamboat Springs, Colorado, October 15, 2010–March 31, 2011 while the TWP-D AOS will be stationed at the ARM Darwin site. The maiden deployments of the MAOS-A and MAOS-C platforms will be during the Ganges Valley Experiment (GVAX) scheduled for April 2011–April 2012. In addition to the ground-based AOS platforms, thee major instrument builds for the AAF are also being undertaken (new trace gas package [NO

  19. Plutonium aerosol fluxes and pulmonary exposure rates during resuspension from bare soils near a chemical separation facility

    SciTech Connect

    Shinn, J.H.; Homan, D.N.; Gay, D.D.

    1982-11-01

    The purpose of this study was to examine the plutonium aerosol fluxes (Curies per ground area per unit time) from a bare soil near a chemical separation facility and to determine the characteristics of the plutonium-bearing aerosols, which are of consequence in deposition of the alpha-emitters into the lung. These characteristics are the plutonium aerosol concentration (Curies per unit volume of air), the particle size distribution, the radioactivity size distribution, the enhancement factors, and others. The site was the agricultural field adjacent to H-area of Savannah River Plant near Aiken, South Carolina, where low-level releases of /sup 239/Pu and /sup 240/Pu occurred from 1967 through 1974. The releases then changed primarily to /sup 238/Pu. Results indicate that plutonium aerosol concentrations were not greatly increased by removing the vegetation and cultivating the field. Following a rain which stabilized the surface /sup 239/Pu concentrations were 37% of normal to 144% of normal as the field dried. The /sup 239/Pu concentration was broadly distributed over particle sizes and had MAD 2.7 ..mu..m. The /sup 239/Pu concentration distributions were found to be 12% respirable and the maximum concentration observed, 4.94 x 10/sup -17/ Ci m/sup -3/, amounted to an inconsequential exposure of less than 10/sup -5/ lifetime background dose for 100 days exposure. /sup 239/Pu flux was not greatly increased as the dust flux increased because /sup 239/Pu activity of the aerosols decreased with time to counteract the increased dust flux.

  20. The Multi-Sensor Aerosol Products Sampling System (MAPSS) for Integrated Analysis of Satellite Retrieval Uncertainties

    NASA Technical Reports Server (NTRS)

    Ichoku, Charles; Petrenko, Maksym; Leptoukh, Gregory

    2010-01-01

    Among the known atmospheric constituents, aerosols represent the greatest uncertainty in climate research. Although satellite-based aerosol retrieval has practically become routine, especially during the last decade, there is often disagreement between similar aerosol parameters retrieved from different sensors, leaving users confused as to which sensors to trust for answering important science questions about the distribution, properties, and impacts of aerosols. As long as there is no consensus and the inconsistencies are not well characterized and understood ', there will be no way of developing reliable climate data records from satellite aerosol measurements. Fortunately, the most globally representative well-calibrated ground-based aerosol measurements corresponding to the satellite-retrieved products are available from the Aerosol Robotic Network (AERONET). To adequately utilize the advantages offered by this vital resource,., an online Multi-sensor Aerosol Products Sampling System (MAPSS) was recently developed. The aim of MAPSS is to facilitate detailed comparative analysis of satellite aerosol measurements from different sensors (Terra-MODIS, Aqua-MODIS, Terra-MISR, Aura-OMI, Parasol-POLDER, and Calipso-CALIOP) based on the collocation of these data products over AERONET stations. In this presentation, we will describe the strategy of the MAPSS system, its potential advantages for the aerosol community, and the preliminary results of an integrated comparative uncertainty analysis of aerosol products from multiple satellite sensors.

  1. Aerosolized delivery of oxime MMB-4 in combination with atropine sulfate protects against soman exposure in guinea pigs.

    PubMed

    Perkins, Michael W; Pierre, Zdenka; Sabnekar, Praveena; Sciuto, Alfred M; Song, Jian; Soojhawon, Iswarduth; Oguntayo, Samuel; Doctor, Bhupendra P; Nambiar, Madhusoodana P

    2012-08-01

    We evaluated the efficacy of aerosolized acetylcholinesterase (AChE) reactivator oxime MMB-4 in combination with the anticholinergic atropine sulfate for protection against respiratory toxicity and lung injury following microinstillation inhalation exposure to nerve agent soman (GD) in guinea pigs. Anesthetized animals were exposed to GD (841 mg/m(3), 1.2 LCt(50)) and treated with endotracheally aerosolized MMB-4 (50 µmol/kg) plus atropine sulfate (0.25 mg/kg) at 30 sec post-exposure. Treatment with MMB-4 plus atropine increased survival to 100% compared to 38% in animals exposed to GD. Decreases in the pulse rate and blood O(2) saturation following exposure to GD returned to normal levels in the treatment group. The body-weight loss and lung edema was significantly reduced in the treatment group. Similarly, bronchoalveolar cell death was significantly reduced in the treatment group while GD-induced increase in total cell count was decreased consistently but was not significant. GD-induced increase in bronchoalveolar protein was diminished after treatment with MMB-4 plus atropine. Bronchoalveolar lavage AChE and BChE activity were significantly increased in animals treated with MMB-4 plus atropine at 24 h. Lung and diaphragm tissue also showed a significant increase in AChE activity in the treatment group. Treatment with MMB-4 plus atropine sulfate normalized various respiratory dynamics parameters including respiratory frequency, tidal volume, peak inspiratory and expiratory flow, time of inspiration and expiration, enhanced pause and pause post-exposure to GD. Collectively, these results suggest that aerosolization of MMB-4 plus atropine increased survival, decreased respiratory toxicity and lung injury following GD inhalation exposure.

  2. Factors influencing the outdoor concentration of carbonaceous aerosols at urban schools in Brisbane, Australia: Implications for children's exposure.

    PubMed

    Crilley, L R; Ayoko, G A; Mazaheri, M; Morawska, L

    2016-01-01

    This comprehensive study aimed to determine the sources and driving factors of organic carbon (OC) and elemental carbon (EC) concentrations in ambient PM2.5 in urban schools. Sampling was conducted outdoors at 25 schools in the Brisbane Metropolitan Area, Australia. Concentrations of primary and secondary OC were quantified using the EC tracer method, with secondary OC accounting for an average of 60%. Principal component analysis distinguished the contributing sources above the background and identified groups of schools with differing levels of primary and secondary carbonaceous aerosols. Overall, the results showed that vehicle emissions, local weather conditions and secondary organic aerosols (SOA) were the key factors influencing concentrations of carbonaceous component of PM2.5 at these schools. These results provide insights into children's exposure to vehicle emissions and SOA at such urban schools. PMID:25953387

  3. EXPOSURE ANALYSIS MODELING SYSTEM (EXAMS): USER MANUAL AND SYSTEM DOCUMENTATION

    EPA Science Inventory

    The Exposure Analysis Modeling System, first published in 1982 (EPA-600/3-82-023), provides interactive computer software for formulating aquatic ecosystem models and rapidly evaluating the fate, transport, and exposure concentrations of synthetic organic chemicals - pesticides, ...

  4. A rhesus macaque (Macaca mulatta) model of aerosol-exposure brucellosis (Brucella suis): pathology and diagnostic implications.

    PubMed

    Yingst, Samuel L; Huzella, Louis M; Chuvala, Lara; Wolcott, Mark

    2010-06-01

    The US Centers for Disease Control and Prevention lists Brucella as a potential bioterrorism threat requiring enhanced diagnostic capacity and surveillance (http://emergency.cdc.gov/bioterrorism/). Successful treatment and management of patients after exposure to biological threat agents depends on accurate and timely diagnosis, but many biothreat agents present with similar, vague clinical signs--commonly referred to as 'flu-like illness'. Diagnosis of brucellosis is notoriously challenging, especially early in infection, and definitive diagnosis may require invasive methods, e.g. bone marrow biopsy. We studied the pathogenesis of Brucella suis aerosol infection in rhesus macaques in an effort to guide the diagnostic algorithm in case of possible intentional exposure of humans. Rhesus proved to be an excellent model for human brucellosis; the data showed that PCR DNA amplification testing of non-invasive diagnostic samples has the potential to definitively detect a point-source outbreak immediately and for several days after exposure. PMID:20223898

  5. Inhalation Exposure and Lung Dose Analysis of Multi-mode Complex Ambient Aerosols

    EPA Science Inventory

    Rationale: Ambient aerosols are complex mixture of particles with different size, shape and chemical composition. Although they are known to cause health hazard, it is not fully understood about causal mechanisms and specific attributes of particles causing the effects. Internal ...

  6. A critique of the U.S. standard for industrial exposure to sodium hydroxide aerosols.

    PubMed

    Cooper, D W; Underhill, D W; Ellenbecker, M J

    1979-05-01

    Published studies of the toxicity of sodium hydroxide aerosols are few. These studies were generally marred by inadequate characterization of particle size and chemical compositon and of the ambient humidity. Because NaOH aerosols can readily undergo reaction with carbon dioxide to form sodium carbonate, a much less alkaline (and less hygroscopic) compound, these shortcomings may warrant a reconsideration of the NaOH standard and the consideration of a Na2CO3 standard.

  7. New capabilities for space-based cloud and aerosols measurements: The Cloud-Aerosol Transport System (CATS)

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Hlavka, D. L.; Palm, S. P.; Hart, W. D.; Nowottnick, E. P.; Vaughan, M.; Rodier, S. D.; Colarco, P. R.; da Silva, A.; Buchard-Marchant, V.

    2013-12-01

    Current uncertainties in cloud and aerosol properties limit our ability to accurately model the Earth's climate system and predict climate change. These limitations are due primarily to difficulties in adequately measuring aerosols and clouds on a global scale. NASA's A-Train satellites provide an unprecedented opportunity to address these uncertainties. In particular, the Cloud-Aerosol Lidar Infrared Pathfinder Spaceborne Observations (CALIPSO) satellite provides vertical profiles of cloud and aerosol properties. The CALIOP lidar onboard CALIPSO has reached its seventh year of operation, well past its expected lifetime. The ATLID lidar on EarthCARE is not expected to launch until 2016 or later. If the CALIOP lidar fails before a new mission is operational, there will be a gap in global lidar measurements. The Cloud-Aerosol Transport System (CATS), built at NASA Goddard Space Flight Center as a payload for the International Space Station (ISS), is set to launch in the summer of 2014. CATS is an elastic backscatter lidar with three wavelengths (1064, 532, 355 nm) and HSRL capability at 532 nm. Depolarization measurements will be made at all three wavelengths. The ISS orbit is a 51 degree inclination orbit at an altitude of about 405 km. This orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three day repeat cycle. Thus, science applications of CATS include cloud and aerosol climate studies, air quality monitoring, and smoke/volcanic plume tracking. The primary science objectives of CATS include: continuing the CALIPSO aerosol and cloud vertical profile data record, providing near real time data to support operational applications such as air quality modeling, and advancing technology in support of future mission development using the HSRL channel. Furthermore, the vertical profiles of cloud and aerosol properties provided by CATS will complement current and future passive satellite

  8. A study of workers' exposures to the inhalable and 'total' aerosol fractions in the primary nickel production industry using mannequins to simulate personal sampling.

    PubMed

    Tsai, P J; Vincent, J H

    2001-07-01

    This paper describes a study that was carried out at work sites in the primary nickel production industry to investigate the difference between inhalable and 'total' aerosol exposures by using the mannequin sampling method, and to compare the results with those from an earlier study where actual workers' personal exposures were assessed in the same way. Experiments were carried out at 21 work sites located in mining, milling, smelting, and refining works of two primary nickel production companies. During sampling, mannequins were used to simulate the physical presence of workers and the 'exposures' of these were obtained for strategic positions at selected work sites. The orientations of each mannequin with respect to the wind were rotated through 90 degrees every hour in order to simulate the approximate orientation-averaging corresponding to actual workers. Two samplers were placed side-by-side on each mannequin: the Institute of Occupational Medicine (IOM) inhalable aerosol sampler, and the 37-mm plastic cassette widely used as a personal sampler for 'total' aerosol. Each collected sample was analyzed to obtain both overall dust and overall nickel content. A total of 116 such sample pairs were collected. The results show that inhalable aerosol exposure levels-for both overall dust and for total nickel content-were consistently and significantly higher than the corresponding total aerosol exposure levels. Weighted least squares linear regression yielded (inhalable/'total') aerosol ratios ranging from 1.38 to 3.90 and 1.20 to 4.01, respectively, for overall dust and for total nickel content for different work sites. Comparison of these results with those from the earlier study of actual workers' personal exposures were in good agreement for most of the work sites studies. However, the actual intensities of exposure using the mannequin sampling method were consistently lower than those obtained from actual workers' personal sampling in our earlier study. The

  9. A study of workers' exposures to the inhalable and 'total' aerosol fractions in the primary nickel production industry using mannequins to simulate personal sampling.

    PubMed

    Tsai, P J; Vincent, J H

    2001-07-01

    This paper describes a study that was carried out at work sites in the primary nickel production industry to investigate the difference between inhalable and 'total' aerosol exposures by using the mannequin sampling method, and to compare the results with those from an earlier study where actual workers' personal exposures were assessed in the same way. Experiments were carried out at 21 work sites located in mining, milling, smelting, and refining works of two primary nickel production companies. During sampling, mannequins were used to simulate the physical presence of workers and the 'exposures' of these were obtained for strategic positions at selected work sites. The orientations of each mannequin with respect to the wind were rotated through 90 degrees every hour in order to simulate the approximate orientation-averaging corresponding to actual workers. Two samplers were placed side-by-side on each mannequin: the Institute of Occupational Medicine (IOM) inhalable aerosol sampler, and the 37-mm plastic cassette widely used as a personal sampler for 'total' aerosol. Each collected sample was analyzed to obtain both overall dust and overall nickel content. A total of 116 such sample pairs were collected. The results show that inhalable aerosol exposure levels-for both overall dust and for total nickel content-were consistently and significantly higher than the corresponding total aerosol exposure levels. Weighted least squares linear regression yielded (inhalable/'total') aerosol ratios ranging from 1.38 to 3.90 and 1.20 to 4.01, respectively, for overall dust and for total nickel content for different work sites. Comparison of these results with those from the earlier study of actual workers' personal exposures were in good agreement for most of the work sites studies. However, the actual intensities of exposure using the mannequin sampling method were consistently lower than those obtained from actual workers' personal sampling in our earlier study. The

  10. Effects of aerosols on clear-sky solar radiation in the ALADIN-HIRLAM NWP system

    NASA Astrophysics Data System (ADS)

    Gleeson, Emily; Toll, Velle; Pagh Nielsen, Kristian; Rontu, Laura; Masek, Jan

    2016-05-01

    The direct shortwave radiative effect of aerosols under clear-sky conditions in the Aire Limitee Adaptation dynamique Developpement InterNational - High Resolution Limited Area Model (ALADIN-HIRLAM) numerical weather prediction system was investigated using three shortwave radiation schemes in diagnostic single-column experiments: the Integrated Forecast System (IFS), acraneb2 and the hlradia radiation schemes. The multi-band IFS scheme was formerly used operationally by the European Centre for Medium Range Weather Forecasts (ECMWF) whereas hlradia and acraneb2 are broadband schemes. The former is a new version of the HIRLAM radiation scheme while acraneb2 is the radiation scheme in the ALARO-1 physics package. The aim was to evaluate the strengths and weaknesses of the numerical weather prediction (NWP) system regarding aerosols and to prepare it for use of real-time aerosol information. The experiments were run with particular focus on the August 2010 Russian wildfire case. Each of the three radiation schemes accurately (within ±4 % at midday) simulates the direct shortwave aerosol effect when observed aerosol optical properties are used. When the aerosols were excluded from the simulations, errors of more than +15 % in global shortwave irradiance were found at midday, with the error reduced to +10 % when standard climatological aerosols were used. An error of -11 % was seen at midday if only observed aerosol optical depths at 550 nm, and not observation-based spectral dependence of aerosol optical depth, single scattering albedos and asymmetry factors, were included in the simulations. This demonstrates the importance of using the correct aerosol optical properties. The dependency of the direct radiative effect of aerosols on relative humidity was tested and shown to be within ±6 % in this case. By modifying the assumptions about the shape of the IFS climatological vertical aerosol profile, the inherent uncertainties associated with assuming fixed vertical

  11. A High-Spatial-Resolution, Localized MODIS Aerosol Optical Depth Product for Use in Air Quality Exposure Assessment During Large Wildfire Smoke Events

    NASA Astrophysics Data System (ADS)

    McCarthy, M. C.; Raffuse, S. M.; DeWinter, J. L.; Craig, K. J.; Jumbam, L. K.; Fruin, S.; Lurmann, F.

    2011-12-01

    Aerosol optical depth (AOD) has potential use for determining the intra-urban variability of airborne particulate matter exposure during wildfire events; however, the standard Moderate Resolution Imaging Spectroradiometer (MODIS) AOD products have limitations for this application. Specifically, the 10x10 km resolution is too coarse for intra-urban population exposure assessments, the assumed aerosol optical properties are not representative of biomass burning aerosol, and the cloud masking algorithm misinterprets heavy smoke as clouds. We developed a localized MODIS AOD product at 1.5 and 2.5 km resolutions and tested the performance in northern California during the 2008 wildfires. The localized product's algorithm uses local biomass burning aerosol optical properties, local surface reflectance data, and a relaxed cloud filter. During the 2008 season, persistent heavy smoke was produced over northern California and the San Joaquin Valley for over two months. As California is both highly populated and covered with a relatively dense network of ground-based aerosol monitoring stations, this event provided an excellent opportunity to develop the AOD product and test its ability to predict aerosol concentrations on the ground to assess population exposure. We will present our methodology and discuss its potential for air quality and public health applications.

  12. Photoacoustic sensor system for the quantification of soot aerosols (abstract)

    NASA Astrophysics Data System (ADS)

    Haisch, C.; Beck, H.; Niessner, R.

    2003-01-01

    The influence of soot particles on human health as well as global and local climate is well established by now. Hence, the need for fast and sensitive soot detection in urban and remote areas is obvious. The state of the art thermochemical detection methods for soot analysis is based on filter sampling and subsequent wet chemical analysis and combustion, which requires laborious and time consuming sample preparation. Due to the integration on a filter, a time-resolved analysis is not possible. The presented photoacoustic sensor system is optimized for a highly sensitive and fast on-line and in situ quantification of soot. Soot particles, as classical "black absorbers," absorb electromagnetic radiation over the whole spectrum. Two similar systems are introduced. The first system is designed for the development and testing of combustion engines, mainly the next generation of diesel engines. In the next decade, legal thresholds for extremely low particle emissions are foreseen. Their implementation will be only possible if a time-resolved soot detection with sufficient sensitivity can be realized as the highest particle emissions from diesel engines are generated only for seconds during load changes. During a load change, the emitted soot concentrations can rise several orders of magnitude for only a period of few seconds. The system combines a time resolution of 1 s (sampling rate 1 Hz) with an aerosol mass sensitivity better than 10 μg m-3. Up to a maximum dimension of about 800 nm the signal is independent of the particle size. The systems consist of two photoacoustic cells, which are operated in a differential mode to avoid cross sensitivities. The cells are built as acoustical resonators to increase sensitivity. A diode laser with a wavelength of 810 nm and an output power of 1.1 W is employed for excitation. Its collimated beam passes first through the reference cell and then through the measurement cell. To avoid condensation of water, the cells are heated to

  13. New Measurements of Aerosol Vertical Structure from Space using the NASA Geoscience Laser Altimeter System (GLAS): Applications for Aerosol Transport Models

    NASA Technical Reports Server (NTRS)

    Welton, E. J.; Spinhime, J.; Palm, S.; Hlavka, D.; Hart, W.; Ginoux, P.; Chin, M.; Colarco, P.

    2004-01-01

    In the past, satellite measurements of aerosols have only been possible using passive sensors. Analysis of passive satellite data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth,s climate. However, direct measurement of aerosol vertical distribution has not been possible using only the passive data. Knowledge of aerosol vertical distribution is important to correctly assess the impact of aerosol absorption, for certain atmospheric correction procedures, and to help constrain height profiles in aerosol transport models. On January 12,2003 NASA launched the first satellite-based lidar, the Geoscience Laser Altimeter System (GLAS), onboard the ICESat spacecraft. GLAS is both an altimeter and an atmospheric lidar, and obtains direct measurements of aerosol and cloud heights. Here we show an overview of GLAS, provide an update of its current status, and discuss how GLAS data will be useful for modeling efforts. In particular, a strategy of using GLAS to characterize the height profile of dust plumes over source regions will be presented, along with initial results. Such information can be used to validate and improve output from aerosol transport models. Aerosol height profile comparisons between GLAS and transport models will be shown for regions downwind of aerosol sources. We will also discuss the feasibility of assimilating GLAS profiles into the models in order to improve their output.

  14. New Measurements of Aerosol Vertical Structure from Space Using the NASA Geoscience Laser Altimeter System (GLAS): Applications for Aerosol Transport Models

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Ginoux, Paul; Colarco, Peter; Chin, Mian; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis; Hart, William

    2003-01-01

    In the past, satellite measurements of aerosols have only been possible using passive sensors. Analysis of passive satellite data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth s climate. However, direct measurement of aerosol vertical distribution has not been possible using only the passive data. Knowledge of aerosol vertical distribution is important to correctly assess the impact of aerosol absorption, for certain atmospheric correction procedures, and to help constrain height profiles in aerosol transport models. On January 12,2003 NASA launched the first satellite-based lidar, the Geoscience Laser Altimeter System (GLAS), onboard the ICESat spacecraft. GLAS is both an altimeter and an atmospheric lidar, and obtains direct measurements of aerosol and cloud heights. Here we show an overview of GLAS, provide an update of its current status, and discuss how GUS data will be useful for modeling efforts. In particular, a strategy of using GLAS to characterize the height profile of dust plumes over source regions will be presented, along with initial results. Such information can be used to validate and improve output from aerosol transport models. Aerosol height profile comparisons between GLAS and transport models will be shown for regions downwind of aerosol sources. We will also discuss the feasibility of assimilating GLAS profiles into the models in order to improve their output,

  15. A View of Earth's Aerosol System from Space to Your Office Chair

    NASA Technical Reports Server (NTRS)

    Colarco, Peter

    2008-01-01

    Aerosols are tiny particles and droplets suspended in the air. Each day you breathe in about 10 billion of them, about a half a million per breath. They are formed in nature by volcanoes, dust storms, sea spray, and emissions from vegetation. Humans create aerosols and alter their natural sources by burning fossil fuels and modifying land cover. Fires are another important source of aerosols; some are natural, such as wildfires started by lightning strikes, while others are from human-caused burning of vegetation for cooking, heating, and land clearing. Aerosols have complex effects on Earth's climate. In general, they cool the surface by reflecting (scattering) radiation from the sun back into space. Dust and smoke absorb solar radiation and heat the atmosphere where they are concentrated. Aerosols change the properties of clouds. Indeed, it would be very difficult to form clouds in the atmosphere without aerosols to act as 'seeds' for water to condense on. In aerosol polluted environments clouds tend to have smaller droplets than clouds formed in cleaner environments; these polluted clouds appear brighter from space because they reflect more sunlight, and they may persist longer and not rain as intensely. Aerosols also affect local air quality and visibility. Data collected by NASA satellites over the past decade have provided an unprecedented view of Earth's aerosol distribution and dramatically increased our understanding of where aerosols come from and just how far they travel in the atmosphere. In this talk I will discuss observations of aerosols from space and how they inform numerical transport models attempting to simulate the global aerosol system.

  16. Analysis of DIAL/HSRL aerosol backscatter and extinction profiles during the SEAC4RS campaign with an aerosol assimilation system

    NASA Astrophysics Data System (ADS)

    Weaver, C. J.; da Silva, A. M., Jr.; Colarco, P. R.; Randles, C. A.

    2015-12-01

    We retrieve aerosol concentrations and optical information from vertical profiles of airborne 532 nm extinction and 532 and 1064 nm backscatter measurements made during the SEAC4RS summer 2013 campaign. The observations are from the High Spectral Resolution Lidar (HSRL) Airborne Differential Absorption Lidar (DIAL) on board the NASA DC-8. Instead of retrieving information about aerosol microphysical properties such as indexes of refraction, we seek information more directly applicable to an aerosol transport model - in our case the Goddard Chemistry Aerosol Radiation and Transport (GOCART) module used in the GEOS-5 Earth modeling system. A joint atmosphere/aerosol mini-reanalysis was performed for the SEAC4RS period using GEOS-5. The meteorological reanalysis followed the MERRA-2 atmospheric reanalysis protocol, and aerosol information from MODIS, MISR, and AERONET provided a constraint on the simulated aerosol optical depth (i.e., total column loading of aerosols). We focus on the simulated concentrations of 10 relevant aerosol species simulated by the GOCART module: dust, sulfate, and organic and black carbon. Our first retrieval algorithm starts with the SEAC4RS mini-reanalysis and adjusts the concentration of each GOCART aerosol species so that differences between the observed and simulated backscatter and extinction measurements are minimized. In this case, too often we are unable to simulate the observations by simple adjustment of the aerosol concentrations. A second retrieval approach adjusts both the aerosol concentrations and the optical parameters (i.e., assigned mass extinction efficiency) associated with each GOCART species. We present results from DC-8 flights over smoke from forest fires over the western US using both retrieval approaches. Finally, we compare our retrieved quantities with in-situ observations of aerosol absorption, scattering, and mass concentrations at flight altitude.

  17. High-resolution MODIS aerosol retrieval during wildfire events in California for use in exposure assessment

    NASA Astrophysics Data System (ADS)

    Raffuse, Sean M.; McCarthy, Michael C.; Craig, Kenneth J.; DeWinter, Jennifer L.; Jumbam, Loayeh K.; Fruin, Scott; James Gauderman, W.; Lurmann, Frederick W.

    2013-10-01

    Retrieval of aerosol optical depth (AOD) from the Moderate Resolution Imaging Spectroradiometer (MODIS) using the Collection 5 (C005) algorithm provides large-scale (10 × 10 km) estimates that can be used to predict surface layer concentrations of particulate matter with aerodynamic diameter smaller than 2.5 µm (PM2.5). However, these large-scale estimates are not suitable for identifying intraurban variability of surface PM2.5 concentrations during wildfire events when individual plumes impact populated areas. We demonstrate a method for providing high-resolution (2.5 km) kernel-smoothed estimates of AOD over California during the 2008 northern California fires. The method uses high-resolution surface reflectance ratios of the 0.66 and 2.12 µm channels, a locally derived aerosol optical model characteristic of fresh wildfire plumes, and a relaxed cloud filter. Results show that the AOD derived for the 2008 northern California fires outperformed the standard product in matching observed aerosol optical thickness at three coastal Aerosol Robotic Network sites and routinely explained more than 50% of the variance in hourly surface PM2.5 concentrations observed during the wildfires.

  18. The Cloud-Aerosol Transport System (CATS): a New Lidar for Aerosol and Cloud Profiling from the International Space Station

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; McGill, Matthew J.; Yorks, John E.; Hlavka, Dennis L.; Hart, William D.; Palm, Stephen P.; Colarco, Peter R.

    2011-01-01

    Spaceborne lidar profiling of aerosol and cloud layers has been successfully implemented during a number of prior missions, including LITE, ICESat, and CALIPSO. Each successive mission has added increased capability and further expanded the role of these unique measurements in wide variety of applications ranging from climate, to air quality, to special event monitoring (ie, volcanic plumes). Many researchers have come to rely on the availability of profile data from CALIPSO, especially data coincident with measurements from other A-Train sensors. The CALIOP lidar on CALIPSO continues to operate well as it enters its fifth year of operations. However, active instruments have more limited lifetimes than their passive counterparts, and we are faced with a potential gap in lidar profiling from space if the CALIOP lidar fails before a new mission is operational. The ATLID lidar on EarthCARE is not expected to launch until 2015 or later, and the lidar component of NASA's proposed Aerosols, Clouds, and Ecosystems (ACE) mission would not be until after 2020. Here we present a new aerosol and cloud lidar that was recently selected to provide profiling data from the International Space Station (ISS) starting in 2013. The Cloud-Aerosol Transport System (CATS) is a three wavelength (1064, 532, 355 nm) elastic backscatter lidar with HSRL capability at 532 nm. Depolarization measurements will be made at all wavelengths. The primary objective of CATS is to continue the CALIPSO aerosol and cloud profile data record, ideally with overlap between both missions and EarthCARE. In addition, the near real time data capability of the ISS will enable CATS to support operational applications such as air quality and special event monitoring. The HSRL channel will provide a demonstration of technology and a data testbed for direct extinction retrievals in support of ACE mission development. An overview of the instrument and mission will be provided, along with a summary of the science

  19. Radiation Exposure Monitoring and Information Transmittal System.

    2005-06-23

    Version 01 The Radiation Exposure Monitoring and Information Transmittal (REMIT) system is designed to assist U.S. Nuclear Regulatory Commission (NRC) licensees in meeting the reporting requirements of the Revised 10 CFR Parts 20.1001 through 20.2401 as outlined in Regulatory Guide 8.7, Rev.1, Instructions for Recording and Reporting Occupational Exposure Data. REMIT is a PC‑based menu driven system that facilitates the manipulation of data base files to record and report radiation exposure information. REMIT is designedmore » to be user‑friendly and contains the full text of Regulatory Guide 8.7, Rev.1, on‑line as well as context‑sensitive help throughout the program. The user can enter data directly from NRC Forms 4 or 5. REMIT allows the user to view the individual's exposure in relation to regulatory or administrative limits and will alert the user to exposures in excess of these limits. The system also provides for the calculation and summation of dose from intakes and the determination of the dose to the maximally exposed extremity for the monitoring year. REMIT can produce NRC Forms 4 and 5 in paper and electronic format and can import/export data from ASCII and data base files. Additional information is available from the web page www.reirs.com.« less

  20. Effects of single and repeated inhalation exposure of Syrian hamsters to aerosols of /sup 144/CeO/sub 2/

    SciTech Connect

    Lundgren, D.L.; Hahn, F.F.; McClellan, R.O.

    1982-05-01

    Male Syrian hamsters (84 days old at the time of the initial exposure) were repeatedly exposed by inhalation at approximately 60-day intervals for 1 year (seven exposures) to aerosols of /sup 144/CeO/sub 2/ to reestablish lung burdens of 0.4, 2.0, or 10 ..mu..Ci of /sup 144/Ce. Other hamsters were exposed once when either 84, 220, or 360 days old to achieve similar initial lung burdens. Primary lung tumors were observed in 7 of 197 hamsters repeatedly exposed to /sup 144/CeO/sub 2/ that died between 177 and 685 days after the initial inhalation exposure. The cumulative adsorbed ..beta..-radiation doses to the lungs of these hamsters were 14,000 to 50,000 rad. Primary lung tumors also were observed in 6 of 153 hamsters exposed once to /sup 144/CeO/sub 2/ when 84 or 220 days old that died between 270 and 695 days after exposure. The cumulative ..beta..-radiation doses to the lungs of these hamsters were 6000 to 21,000 rad. Lung tumors were not observed in hamsters exposed when 360 days old or in control hamsters. The incidences of primary lung tumors were more dependent on the cumulative dose to the lung than the radiation dose pattern that resulted in the cumulative dose.

  1. Aerosol-Cloud-Precipitation Interactions in the Climate System

    NASA Astrophysics Data System (ADS)

    Andreae, M. O.

    2015-12-01

    Aerosols serve as cloud condensation nuclei (CCN) and thus have a powerful effect on cloud properties. Increased aerosol concentrations resulting from pollution lead to higher cloud droplet concentrations, but smaller droplet sizes. This in turn affects the physical processes inside clouds that lead to the initiation of precipitation. Depending on a number of factors, including aerosol composition, atmospheric stability, and cloud water content, increasing CCN concentrations may either decrease or increase rainfall. In convective clouds, early rain formation is suppressed, which makes more water and energy available to rise higher in the atmosphere and form ice particles. This may invigorate the dynamics of convection, encourage the formation of hail and lightning, and enhance the transport of materials to the upper troposphere. In turn, cloud processing also affects the concentrations, composition, and distribution of atmospheric aerosols. In order to understand and quantify the effects of air pollution on climate, and precipitation in particular, knowledge of natural abundance and characteristics of aerosols is as essential as the observation of perturbed conditions. I will present recent advances in the conceptual understanding of aerosol-precipitation interactions, as well as results of measurements on aerosol and cloud characteristics in pristine and polluted conditions.

  2. Aerosol Optical Depth As a Measure of Particulate Exposure Using Imputed Censored Data, and Relationship with Childhood Asthma Hospital Admissions for 2004 in Athens, Greece

    PubMed Central

    Higgs, Gary; Sterling, David A; Aryal, Subhash; Vemulapalli, Abhilash; Priftis, Kostas N; Sifakis, Nicolas I

    2015-01-01

    An understanding of human health implications from atmosphere exposure is a priority in both the geographic and the public health domains. The unique properties of geographic tools for remote sensing of the atmosphere offer a distinct ability to characterize and model aerosols in the urban atmosphere for evaluation of impacts on health. Asthma, as a manifestation of upper respiratory disease prevalence, is a good example of the potential interface of geographic and public health interests. The current study focused on Athens, Greece during the year of 2004 and (1) demonstrates a systemized process for aligning data obtained from satellite aerosol optical depth (AOD) with geographic location and time, (2) evaluates the ability to apply imputation methods to censored data, and (3) explores whether AOD data can be used satisfactorily to investigate the association between AOD and health impacts using an example of hospital admission for childhood asthma. This work demonstrates the ability to apply remote sensing data in the evaluation of health outcomes, that the alignment process for remote sensing data is readily feasible, and that missing data can be imputed with a sufficient degree of reliability to develop complete datasets. Individual variables demonstrated small but significant effect levels on hospital admission of children for AOD, nitrogen oxides (NOx), relative humidity (rH), temperature, smoke, and inversely for ozone. However, when applying a multivari-able model, an association with asthma hospital admissions and air quality could not be demonstrated. This work is promising and will be expanded to include additional years. PMID:25987842

  3. A review of exposure conditions and possible health effects associated with aerosol and vapour from low-aromatic oil-based drilling fluids.

    PubMed

    Eide, I

    1990-04-01

    This paper reviews investigations on possible health effects after inhalation of aerosol and vapour from the low-aromatic oil-based drilling fluids which have replaced the diesel-based fluids. The main advantage of the low-aromatic base oils with respect to health hazard is their lower volatility. However, some aliphatic and naphthenic hydrocarbons are distributed more efficiently to the brain than are the corresponding aromatic ones. Reducing the content of aromatic hydrocarbons becomes particularly important when the upper end of the boiling point range is sufficiently high for the base oil to contain carcinogenic polycyclic aromatic hydrocarbons (PAH). As a result of enclosure and local extract ventilation it has been possible to reduce time-weighted average concentrations of aerosol and vapour to below 100 mg m-3. Effects on the central nervous system have only been observed at higher concentrations of the actual hydrocarbons, and male rat hydrocarbon nephropathy is not considered predictive of a normal human response. Insufficient information is available on possible long-term effects of exposure to the low-aromatic oil-based drilling fluids, especially regarding carcinogenicity and changes in the lungs. PMID:2205144

  4. Aerosol optical depth as a measure of particulate exposure using imputed censored data, and relationship with childhood asthma hospital admissions for 2004 in athens, Greece.

    PubMed

    Higgs, Gary; Sterling, David A; Aryal, Subhash; Vemulapalli, Abhilash; Priftis, Kostas N; Sifakis, Nicolas I

    2015-01-01

    An understanding of human health implications from atmosphere exposure is a priority in both the geographic and the public health domains. The unique properties of geographic tools for remote sensing of the atmosphere offer a distinct ability to characterize and model aerosols in the urban atmosphere for evaluation of impacts on health. Asthma, as a manifestation of upper respiratory disease prevalence, is a good example of the potential interface of geographic and public health interests. The current study focused on Athens, Greece during the year of 2004 and (1) demonstrates a systemized process for aligning data obtained from satellite aerosol optical depth (AOD) with geographic location and time, (2) evaluates the ability to apply imputation methods to censored data, and (3) explores whether AOD data can be used satisfactorily to investigate the association between AOD and health impacts using an example of hospital admission for childhood asthma. This work demonstrates the ability to apply remote sensing data in the evaluation of health outcomes, that the alignment process for remote sensing data is readily feasible, and that missing data can be imputed with a sufficient degree of reliability to develop complete datasets. Individual variables demonstrated small but significant effect levels on hospital admission of children for AOD, nitrogen oxides (NOx), relative humidity (rH), temperature, smoke, and inversely for ozone. However, when applying a multivari-able model, an association with asthma hospital admissions and air quality could not be demonstrated. This work is promising and will be expanded to include additional years. PMID:25987842

  5. Effects of subchronic exposures to concentrated ambient particles (CAPs) in mice. II. The design of a CAPs exposure system for biometric telemetry monitoring.

    PubMed

    Maciejczyk, Polina; Zhong, Mianhua; Li, Qian; Xiong, Judy; Nadziejko, Christine; Chen, Lung Chi

    2005-04-01

    We modified, assembled, tested, and validated the versatile aerosol concentration enrichment system (VACES) developed by Sioutas et al. (1999) for use in a subchronic experiment that involved exposure of mice in vivo and of respiratory epithelial cells in vitro to concentrated ambient particles (CAPs). Since the labor-intensive nose-only exposure regimen is not an option in a long-term experiment, a whole-body exposure mouse chamber was designed specifically for use with the VACES. The exposure system concsists of a stainless-steel (SS) tub with 32 cubicles (1 mouse per cubicle) separated by perforated SS sheets. The tops of these cubicles are covered with perforated plastic sheets to allow telemetry monitoring during the exposure. In each exposure chamber, perforated aluminum tubes are used to distribute CAPs evenly (within 2% difference) throughout the exposure chamber. The exhaust consists of perforated aluminum tubes covered with a urine shield. The modification to the original design of the VACES facilitated the operation of the system in a subchronic study. Mass flow controllers maintain a constant flow rate into the exposure chambers. For a sham control exposure, the identical system is used, except that a HEPA filter at the inlet to the VACES removes 98% of ambient particles. The entire system allow for simultaneous exposure of 64 mice to CAPs, with an equal number of sham-expose mice as controls. Telemetry receives have been modified so that 16 mice per group with electrocardiograph (EKG) transmitters can be monitored during exposure. Furthermore, a BioSampler is used to collect CAPs (one sample per day) for the in vitro exposures. In this article, the assessments of flow and particle distribution of the exposure chamber as well as the performance of the system during the subchronic exposure experiment are described. PMID:15804936

  6. Vertical profiles of atmospheric fluorescent aerosols observed by a mutil-channel lidar spectrometer system

    NASA Astrophysics Data System (ADS)

    Huang, Z.; Huang, J.; Zhou, T.; Sugimoto, N.; Bi, J.

    2015-12-01

    Zhongwei Huang1*, Jianping Huang1, Tian Zhou1, Nobuo Sugimoto2, Jianrong Bi1 and Jinsen Shi11Key Laboratory for Semi-Arid Climate Change of the Ministry of Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou, China. 2Atmospheric Environment Division, National Institutes for Environmental Studies, Tsukuba, Japan Email: huangzhongwei@lzu.edu.cn Abstract Atmospheric aerosols have a significant impact on regional and globe climate. The challenge in quantifying aerosol direct radiative forcing and aerosol-cloud interactions arises from large spatial and temporal heterogeneity of aerosol concentrations, compositions, sizes, shape and optical properties (IPCC, 2007). Lidar offers some remarkable advantages for determining the vertical structure of atmospheric aerosols and their related optical properties. To investigate the characterization of atmospheric aerosols (especially bioaerosols) with high spatial and temporal resolution, we developed a Raman/fluorescence/polarization lidar system employed a multi-channel spectrometer, with capabilities of providing measurements of Raman scattering and laser-induced fluorescence excitation at 355 nm from atmospheric aerosols. Meanwhile, the lidar system operated polarization measurements both at 355nm and 532nm wavelengths, aiming to obtain more information of aerosols. It employs a high power pulsed laser and a received telescope with 350mm diameter. The receiver could simultaneously detect a wide fluorescent spectrum about 178 nm with spectral resolution 5.7 nm, mainly including an F/3.7 Crossed Czerny-Turner spectrograph, a grating (1200 gr/mm) and a PMT array with 32 photocathode elements. Vertical structure of fluorescent aerosols in the atmosphere was observed by the developed lidar system at four sites across northwest China, during 2014 spring field observation that conducted by Lanzhou University. It has been proved that the developed lidar could detect the fluorescent aerosols with high temporal and

  7. Pulmonary cellular effects in rats following aerosol exposures to ultrafine Kevlar aramid fibrils: evidence for biodegradability of inhaled fibrils.

    PubMed

    Warheit, D B; Kellar, K A; Hartsky, M A

    1992-10-01

    Previous chronic inhalation studies have shown that high concentrations of Kevlar fibrils produced fibrosis and cystic keratinizing tumors in rats following 2-year inhalation exposures. The current studies were undertaken to evaluate mechanisms and to assess the toxicity of inhaled Kevlar fibrils relative to other reference materials. Rats were exposed to ultrafine Kevlar fibers (fibrils) for 3 or 5 days at concentrations ranging from 600-1300 fibers/cc (gravimetric concentrations ranging from 2-13 mg/m3). A complete characterization of the fiber aerosol and dose was carried out. These measurements included gravimetric concentrations, mass median aerodynamic diameter, fiber number, and count median lengths and diameters of the aerosol. Following exposures, cells and fluids from groups of sham- and fiber-exposed animals were recovered by bronchoalveolar lavage (BAL). Alkaline phosphatase, lactate dehydrogenase (LDH), protein, and N-acetyl glucosaminidase (NAG) values were measured in BAL fluids at several time points postexposure. Alveolar macrophages were cultured and studied for morphology, chemotaxis, and phagocytosis by scanning electron microscopy. The lungs of additional exposed animals were processed for deposition, cell labeling, retained dose, and lung clearance studies, as well as fiber dimensions (from digested lung tissue), histopathology, and transmission electron microscopy. Five-day exposures to Kevlar fibrils elicited a transient granulocytic inflammatory response with concomitant increases in BAL fluid levels of alkaline phosphatase, NAG, LDH, and protein. Unlike the data from silica and asbestos exposures where inflammation persisted, biochemical parameters returned to control levels at time intervals between 1 week and 1 month postexposure. Macrophage function in Kevlar-exposed alveolar macrophages was not significantly different from sham controls at any time period. Cell labeling studies were carried out immediately after exposure, as well as 1

  8. Acute lung function responses to ambient acid aerosol exposures in children

    SciTech Connect

    Raizenne, M.E.; Burnett, R.T.; Stern, B.; Franklin, C.A.; Spengler, J.D.

    1989-02-01

    We examined the relationship between lung function changes and ambient acid aerosol episodes in children attending a residential summer camp. Young females (112) performed daily spirometry, and 96 were assessed on one occasion for airway hyperresponsiveness using a methacholine bronchoprovocation test. Air quality measurements were performed on site and four distinct acid aerosol episodes were observed during the 41-day study. The maximum values observed during the 41-day study were: O/sub 3/ at 143 ppb; H/sub 2/SO/sub 4/ at 47.7 micrograms/m/sup 3/; and (H+) at 550 nmole/m/sup 3/. Maximum decrements of 3.5 and 7% for FEV1 and PEF, respectively, were observed to be associated with the air pollution episodes. There was some evidence of a differential lung function response to the episodes where children with a positive response to a methacholine challenge had larger decrements compared to their nonresponsive counterparts.

  9. Acute lung function responses to ambient acid aerosol exposures in children.

    PubMed

    Raizenne, M E; Burnett, R T; Stern, B; Franklin, C A; Spengler, J D

    1989-02-01

    We examined the relationship between lung function changes and ambient acid aerosol episodes in children attending a residential summer camp. Young females (112) performed daily spirometry, and 96 were assessed on one occasion for airway hyperresponsiveness using a methacholine bronchoprovocation test. Air quality measurements were performed on site and four distinct acid aerosol episodes were observed during the 41-day study. The maximum values observed during the 41-day study were: O3 at 143 ppb; H2SO4 at 47.7 micrograms/m3; and [H+] at 550 nmole/m3. Maximum decrements of 3.5 and 7% for FEV1 and PEF, respectively, were observed to be associated with the air pollution episodes. There was some evidence of a differential lung function response to the episodes where children with a positive response to a methacholine challenge had larger decrements compared to their nonresponsive counterparts.

  10. Development of the Ensemble Navy Aerosol Analysis Prediction System (ENAAPS) and its application of the Data Assimilation Research Testbed (DART) in support of aerosol forecasting

    NASA Astrophysics Data System (ADS)

    Rubin, J. I.; Reid, J. S.; Hansen, J. A.; Anderson, J. L.; Collins, N.; Hoar, T. J.; Hogan, T.; Lynch, P.; McLay, J.; Reynolds, C. A.; Sessions, W. R.; Westphal, D. L.; Zhang, J.

    2015-10-01

    An ensemble-based forecast and data assimilation system has been developed for use in Navy aerosol forecasting. The system makes use of an ensemble of the Navy Aerosol Analysis Prediction System (ENAAPS) at 1° × 1°, combined with an Ensemble Adjustment Kalman Filter from NCAR's Data Assimilation Research Testbed (DART). The base ENAAPS-DART system discussed in this work utilizes the Navy Operational Global Analysis Prediction System (NOGAPS) meteorological ensemble to drive offline NAAPS simulations coupled with the DART Ensemble Kalman Filter architecture to assimilate bias-corrected MODIS Aerosol Optical Thickness (AOT) retrievals. This work outlines the optimization of the 20-member ensemble system, including consideration of meteorology and source-perturbed ensemble members as well as covariance inflation. Additional tests with 80 meteorological and source members were also performed. An important finding of this work is that an adaptive covariance inflation method, which has not been previously tested for aerosol applications, was found to perform better than a temporally and spatially constant covariance inflation. Problems were identified with the constant inflation in regions with limited observational coverage. The second major finding of this work is that combined meteorology and aerosol source ensembles are superior to either in isolation and that both are necessary to produce a robust system with sufficient spread in the ensemble members as well as realistic correlation fields for spreading observational information. The inclusion of aerosol source ensembles improves correlation fields for large aerosol source regions such as smoke and dust in Africa, by statistically separating freshly emitted from transported aerosol species. However, the source ensembles have limited efficacy during long range transport. Conversely, the meteorological ensemble produces sufficient spread at the synoptic scale to enable observational impact through the ensemble data

  11. Development of the Ensemble Navy Aerosol Analysis Prediction System (ENAAPS) and its application of the Data Assimilation Research Testbed (DART) in support of aerosol forecasting

    NASA Astrophysics Data System (ADS)

    Rubin, Juli I.; Reid, Jeffrey S.; Hansen, James A.; Anderson, Jeffrey L.; Collins, Nancy; Hoar, Timothy J.; Hogan, Timothy; Lynch, Peng; McLay, Justin; Reynolds, Carolyn A.; Sessions, Walter R.; Westphal, Douglas L.; Zhang, Jianglong

    2016-03-01

    An ensemble-based forecast and data assimilation system has been developed for use in Navy aerosol forecasting. The system makes use of an ensemble of the Navy Aerosol Analysis Prediction System (ENAAPS) at 1 × 1°, combined with an ensemble adjustment Kalman filter from NCAR's Data Assimilation Research Testbed (DART). The base ENAAPS-DART system discussed in this work utilizes the Navy Operational Global Analysis Prediction System (NOGAPS) meteorological ensemble to drive offline NAAPS simulations coupled with the DART ensemble Kalman filter architecture to assimilate bias-corrected MODIS aerosol optical thickness (AOT) retrievals. This work outlines the optimization of the 20-member ensemble system, including consideration of meteorology and source-perturbed ensemble members as well as covariance inflation. Additional tests with 80 meteorological and source members were also performed. An important finding of this work is that an adaptive covariance inflation method, which has not been previously tested for aerosol applications, was found to perform better than a temporally and spatially constant covariance inflation. Problems were identified with the constant inflation in regions with limited observational coverage. The second major finding of this work is that combined meteorology and aerosol source ensembles are superior to either in isolation and that both are necessary to produce a robust system with sufficient spread in the ensemble members as well as realistic correlation fields for spreading observational information. The inclusion of aerosol source ensembles improves correlation fields for large aerosol source regions, such as smoke and dust in Africa, by statistically separating freshly emitted from transported aerosol species. However, the source ensembles have limited efficacy during long-range transport. Conversely, the meteorological ensemble generates sufficient spread at the synoptic scale to enable observational impact through the ensemble data

  12. Feasibility Study For A Spaceborne Ozone/Aerosol Lidar System

    NASA Technical Reports Server (NTRS)

    Campbell, Richard E.; Browell, Edward V.; Ismail, Syed; Dudelzak, Alexander E.; Carswell, Allan I.; Ulitsky, Arkady

    1997-01-01

    Because ozone provides a shield against harmful ultraviolet radiation, determines the temperature profile in the stratosphere, plays important roles in tropospheric chemistry and climate, and is a health risk near the surface, changes in natural ozone layers at different altitudes and their global impact are being intensively researched. Global ozone coverage is currently provided by passive optical and microwave satellite sensors that cannot deliver high spatial resolution measurements and have particular limitations in the troposphere. Vertical profiling DIfferential Absorption Lidars (DIAL) have shown excellent range-resolved capabilities, but these systems have been large, inefficient, and have required continuous technical attention for long term operations. Recently, successful, autonomous DIAL measurements have been performed from a high-altitude aircraft (LASE - Lidar Atmospheric Sensing Experiment), and a space-qualified aerosol lidar system (LITE - Laser In-space Technology Experiment) has performed well on Shuttle. Based on the above successes, NASA and the Canadian Space Agency are jointly studying the feasibility of developing ORACLE (Ozone Research with Advanced Cooperative Lidar Experiments), an autonomously operated, compact DIAL instrument to be placed in orbit using a Pegasus class launch vehicle.

  13. Near Real Time Vertical Profiles of Clouds and Aerosols from the Cloud-Aerosol Transport System (CATS) on the International Space Station

    NASA Astrophysics Data System (ADS)

    Yorks, J. E.; McGill, M. J.; Nowottnick, E. P.

    2015-12-01

    Plumes from hazardous events, such as ash from volcanic eruptions and smoke from wildfires, can have a profound impact on the climate system, human health and the economy. Global aerosol transport models are very useful for tracking hazardous plumes and predicting the transport of these plumes. However aerosol vertical distributions and optical properties are a major weakness of global aerosol transport models, yet a key component of tracking and forecasting smoke and ash. The Cloud-Aerosol Transport System (CATS) is an elastic backscatter lidar designed to provide vertical profiles of clouds and aerosols while also demonstrating new in-space technologies for future Earth Science missions. CATS has been operating on the Japanese Experiment Module - Exposed Facility (JEM-EF) of the International Space Station (ISS) since early February 2015. The ISS orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three-day repeat cycle. The ISS orbit also provides CATS with excellent coverage over the primary aerosol transport tracks, mid-latitude storm tracks, and tropical convection. Data from CATS is used to derive properties of clouds and aerosols including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The measurements of atmospheric clouds and aerosols provided by the CATS payload have demonstrated several science benefits. CATS provides near-real-time observations of cloud and aerosol vertical distributions that can be used as inputs to global models. The infrastructure of the ISS allows CATS data to be captured, transmitted, and received at the CATS ground station within several minutes of data collection. The CATS backscatter and vertical feature mask are part of a customized near real time (NRT) product that the CATS processing team produces within 6 hours of collection. The continuous near real time CATS data

  14. The expanding role of aerosols in systemic drug delivery, gene therapy, and vaccination.

    PubMed

    Laube, Beth L

    2005-09-01

    Aerosolized medications have been used for centuries to treat respiratory diseases. Until recently, inhalation therapy focused primarily on the treatment of asthma and chronic obstructive pulmonary disease, and the pressurized metered-dose inhaler was the delivery device of choice. However, the role of aerosol therapy is clearly expanding beyond that initial focus. This expansion has been driven by the Montreal protocol and the need to eliminate chlorofluorocarbons (CFCs) from traditional metered-dose inhalers, by the need for delivery devices and formulations that can efficiently and reproducibly target the systemic circulation for the delivery of proteins and peptides, and by developments in medicine that have made it possible to consider curing lung diseases with aerosolized gene therapy and preventing epidemics of influenza and measles with aerosolized vaccines. Each of these drivers has contributed to a decade or more of unprecedented research and innovation that has altered how we think about aerosol delivery and has expanded the role of aerosol therapy into the fields of systemic drug delivery, gene therapy, and vaccination. During this decade of innovation, we have witnessed the coming of age of dry powder inhalers, the development of new soft mist inhalers, and improved pressurized metered-dose inhaler delivery as a result of the replacement of CFC propellants with hydrofluoroalkane. The continued expansion of the role of aerosol therapy will probably depend on demonstration of the safety of this route of administration for drugs that have their targets outside the lung and are administered long term (eg, insulin aerosol), on the development of new drugs and drug carriers that can efficiently target hard-to-reach cell populations within the lungs of patients with disease (eg, patients with cystic fibrosis or lung cancer), and on the development of devices that improve aerosol delivery to infants, so that early intervention in disease processes with aerosol

  15. Air ion exposure system for plants

    NASA Technical Reports Server (NTRS)

    Morrow, R. C.; Tibbitts, T. W.

    1987-01-01

    A system was developed for subjecting plants to elevated air ion levels. This system consisted of a rectangular Plexiglas chamber lined with a Faraday cage. Air ions were generated by corona discharge from frayed stainless steel fibers placed at one end of the chamber. This source was capable of producing varying levels of either positive or negative air ions. During plant exposures, environmental conditions were controlled by operating the unit in a growth chamber.

  16. Reexamination of London, England, mortality in relation to exposure to acidic aerosols during 1963-1972 winters

    SciTech Connect

    Thurston, G.D.; Ito, K.; Lippmann, M.; Hayes, C.

    1989-02-01

    Air pollution epidemiology since the 1950s has been able to demonstrate that increases in daily mortality in London, England, were associated with elevated concentrations of index air pollutants, i.e., British Smoke (BS) and sulfur dioxide (SO/sub 2/). In this work, we reanalyze that portion of the 1958-1972 winter mortality-pollution record for which daily direct acid aerosol measurements were made at a central site in London (St. Bartholomew's Medical College). The purposes of these exploratory analyses are to examine the dataset for indications of a relationship between acid aerosol pollution and human mortality and to compare any noted associations with those for other pollution variables. It is found that the log of acid aerosol concentrations is more strongly associated with raw total mortality in bivariate analyses than is BS or SO2, despite the fact that acid data are available from only one central site (versus seven disperse sites for BS and SO/sub 2/). The logarithmic nature of the exposure side of the H/sub 2/SO/sub 4/-mortality relationship implies a saturation model of pollution effects, possibly due to multiday pollution harvesting influences on a susceptible subpopulation. Moreover, mortality-pollution cross-correlation analyses indicate that mortality effects usually follow pollution in time, supporting a causal relationship between the two. The apparent advantage of H/sub 2/SO/sub 4/ over BS in predicting total raw mortality is consistent with the hypothesis that it is the portion of particulate mass of greater health significance and may also allow the development of London mortality results which are more easily transferable to other environments than is the case for existing BS results.

  17. Reexamination of London, England, mortality in relation to exposure to acidic aerosols during 1963-1972 winters.

    PubMed

    Thurston, G D; Ito, K; Lippmann, M; Hayes, C

    1989-02-01

    Air pollution epidemiology since the 1950s has been able to demonstrate that increases in daily mortality in London, England, were associated with elevated concentrations of index air pollutants, i.e., British Smoke (BS) and sulfur dioxide (SO2). In this work, we reanalyze that portion of the 1958-1972 winter mortality-pollution record for which daily direct acid aerosol measurements were made at a central site in London (St. Bartholomew's Medical College). The purposes of these exploratory analyses are to examine the dataset for indications of a relationship between acid aerosol pollution and human mortality and to compare any noted associations with those for other pollution variables. It is found that the log of acid aerosol concentrations is more strongly associated with raw total mortality in bivariate analyses than is BS or SO2, despite the fact that acid data are available from only one central site (versus seven disperse sites for BS and SO2). The logarithmic nature of the exposure side of the H2SO4-mortality relationship implies a saturation model of pollution effects, possibly due to multiday pollution harvesting influences on a susceptible subpopulation. Moreover, mortality-pollution cross-correlation analyses indicate that mortality effects usually follow pollution in time, supporting a causal relationship between the two. The apparent advantage of H2SO4 over BS in predicting total raw mortality is consistent with the hypothesis that it is the portion of particulate mass of greater health significance and may also allow the development of London mortality results which are more easily transferable to other environments than is the case for existing BS results.

  18. Reexamination of London, England, mortality in relation to exposure to acidic aerosols during 1963-1972 winters.

    PubMed Central

    Thurston, G D; Ito, K; Lippmann, M; Hayes, C

    1989-01-01

    Air pollution epidemiology since the 1950s has been able to demonstrate that increases in daily mortality in London, England, were associated with elevated concentrations of index air pollutants, i.e., British Smoke (BS) and sulfur dioxide (SO2). In this work, we reanalyze that portion of the 1958-1972 winter mortality-pollution record for which daily direct acid aerosol measurements were made at a central site in London (St. Bartholomew's Medical College). The purposes of these exploratory analyses are to examine the dataset for indications of a relationship between acid aerosol pollution and human mortality and to compare any noted associations with those for other pollution variables. It is found that the log of acid aerosol concentrations is more strongly associated with raw total mortality in bivariate analyses than is BS or SO2, despite the fact that acid data are available from only one central site (versus seven disperse sites for BS and SO2). The logarithmic nature of the exposure side of the H2SO4-mortality relationship implies a saturation model of pollution effects, possibly due to multiday pollution harvesting influences on a susceptible subpopulation. Moreover, mortality-pollution cross-correlation analyses indicate that mortality effects usually follow pollution in time, supporting a causal relationship between the two. The apparent advantage of H2SO4 over BS in predicting total raw mortality is consistent with the hypothesis that it is the portion of particulate mass of greater health significance and may also allow the development of London mortality results which are more easily transferable to other environments than is the case for existing BS results. PMID:2785034

  19. The Cloud-Aerosol Transport System (CATS): A New Lidar for Aerosol and Cloud Profiling from the International Space Station

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; McGill, Mathew J.; Yorks. John E.; Hlavka, Dennis L.; Hart, William D.; Palm, Stephen P.; Colarco, Peter R.

    2012-01-01

    Spaceborne lidar profiling of aerosol and cloud layers has been successfully implemented during a number of prior missions, including LITE, ICESat, and CALIPSO. Each successive mission has added increased capability and further expanded the role of these unique measurements in wide variety of applications ranging from climate, to air quality, to special event monitoring (ie, volcanic plumes). Many researchers have come to rely on the availability of profile data from CALIPSO, especially data coincident with measurements from other A-Train sensors. The CALIOP lidar on CALIPSO continues to operate well as it enters its fifth year of operations. However, active instruments have more limited lifetimes than their passive counterparts, and we are faced with a potential gap in lidar profiling from space if the CALIOP lidar fails before a new mission is operational. The ATLID lidar on EarthCARE is not expected to launch until 2015 or later, and the lidar component of NASA's proposed Aerosols, Clouds, and Ecosystems (ACE) mission would not be until after 2020. Here we present a new aerosol and cloud lidar that was recently selected to provide profiling data from the International Space Station (ISS) starting in 2013. The Cloud-Aerosol Transport System (CATS) is a three wavelength (1064,532,355 nm) elastic backscatter lidar with HSRL capability at 532 nm. Depolarization measurements will be made at all wavelengths. The primary objective of CATS is to continue the CALIPSO aerosol and cloud profile data record, ideally with overlap between both missions and EarthCARE. In addition, the near real time (NRT) data capability ofthe ISS will enable CATS to support operational applications such as aerosol and air quality forecasting and special event monitoring. The HSRL channel will provide a demonstration of technology and a data testbed for direct extinction retrievals in support of ACE mission development. An overview of the instrument and mission will be provided, along with a

  20. Inhalation exposure systems: design, methods and operation.

    PubMed

    Wong, Brian A

    2007-01-01

    The respiratory system, the major route for entry of oxygen into the body, provides entry for external compounds, including pharmaceutic and toxic materials. These compounds (that might be inhaled under environmental, occupational, medical, or other situations) can be administered under controlled conditions during laboratory inhalation studies. Inhalation study results may be controlled or adversely affected by variability in four key factors: animal environment; exposure atmosphere; inhaled dose; and individual animal biological response. Three of these four factors can be managed through engineering processes. Variability in the animal environment is reduced by engineering control of temperature, humidity, oxygen content, waste gas content, and noise in the exposure facility. Exposure atmospheres are monitored and adjusted to assure a consistent and known exposure for each animal dose group. The inhaled dose, affected by changes in respiration physiology, may be controlled by exposure-specific monitoring of respiration. Selection of techniques and methods for the three factors affected by engineering allows the toxicologic pathologist to study the reproducibility of the fourth factor, the biological response of the animal. PMID:17325967

  1. Long Duration Exposure Facility (LDEF) Archive System

    NASA Technical Reports Server (NTRS)

    Wilson, Brenda K.

    1995-01-01

    The Long Duration Exposure Facility (LDEF) Archive System is designed to provide spacecraft designers and space environment researchers single point access to all available resources from LDEF. These include data, micrographs, photographs, technical reports, papers, hardware and test specimens, as well as technical expertise. Further, the LDEF Archive System is planned such that it could be the foundation for a NASA Space Environments and Effects (SEE) Archive System, with the addition of other spaceflight, laboratory and theoretical space environments and effects data and associated materials. This paper describes the current status and plans of the LDEF Archive System.

  2. Characterization of the Aerosol Instrument Package for the In-service Aircraft Global Observing System IAGOS

    NASA Astrophysics Data System (ADS)

    Bundke, Ulrich; Berg, Marcel; Tettig, Frank; Franke, Harald; Petzold, Andreas

    2015-04-01

    The atmospheric aerosol influences the climate twofold via the direct interaction with solar radiation and indirectly effecting microphysical properties of clouds. The latter has the largest uncertainty according to the last IPPC Report. A measured in situ climatology of the aerosol microphysical properties is needed to reduce the reported uncertainty of the aerosol climate impact. The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System; www.iagos.org) responds to the increasing requests for long-term, routine in situ observational data by using commercial passenger aircraft as measurement platform. However, scientific instrumentation for the measurement of atmospheric constituents requires major modifications before being deployable aboard in-service passenger aircraft. The IAGOS Aerosol Package (IAGOS-P2C) consists of two modified Butanol based CPCs (Model Grimm 5.410) and one optical particle counter (Model Grimm Sky OPC 1.129). A thermodenuder at 250°C is placed upstream the second CPC, thus the number concentrations of the total aerosol and the non-volatile aerosol fraction is measured. The Sky OPC measures the size distribution in the rage theoretically up to 32 μ m. Because of the inlet cut off diameter of D50=3 μ m we are using the 16 channel mode in the range of 250 nm - 2.5 μ m at 1 Hz resolution. In this presentation the IAGOS Aerosol package is characterized for pressure levels relevant for the planned application, down to cruising level of 150 hPa including the inlet system. In our aerosol lab we have tested the system against standard instrumentation with different aerosol test substances in a long duration test. Particle losses are characterized for the inlet system. In addition first results for airborne measurements are shown from a first field campaign.

  3. Effects of ammonium nitrate aerosol exposure on lung structure of normal and elastase-impaired rats and guinea pigs

    SciTech Connect

    Busch, R.H.; Buschbom, R.L.; Cannon, W.C.; Lauhala, K.E.; Miller, F.J.; Graham, J.A.; Smith, L.G.

    1986-04-01

    Groups of rats and guinea pigs with normal lungs and others with elastase-induced emphysema were exposed to NH/sub 4/NO/sub 3/ aerosols of 0.60 mass median aerodynamic diameter at 1 mg/m/sup 3/ for 6 hr/day, 5 days/week, for 4 weeks. Morphologic and morphometric studies were performed on lungs perfused with cacodylate-buffered 2% glutaraldehyde under 20 cm H/sub 2/O pressure at necropsy. The tissues were studied for pathologic change by light and electron microscopy; emphysema was evaluated by subgross and microscopic methods, including changes in mean alveolar chord length using scanning electron microscopy techniques. Elastase produced emphysema to a degree quantifiable by all criteria studied; however, it apparently obscured the effects of nitrate inhalation. The NH/sub 4/NO/sub 3/ exposure (compared to air alone) tended to increase values for pulmonary parameters in normal animals of both species and to decrease them in elastase-treated animals. The NH/sub 4/NO/sub 3/ exposure increased values for lung volume in rats, percentage area affected in elastase-treated rats, and chord length ..beta.. in normal animals of both species. The responses to NH/sub 4/NO/sub 3/ were slight and were not accompanied by any detectable changes in alveolar structure. Therefore, the effects of NH/sub 4/NO/sub 3/ at this exposure level and duration, are regarded as biologically insignificant for rats and guinea pigs.

  4. Climate response of the South Asian monsoon system to anthropogenic aerosols

    SciTech Connect

    Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

    2012-07-13

    The equilibrium climate response to the total effects (direct, indirect and semi-direct effects) of aerosols arising from anthropogenic and biomass burning emissions on the South Asian summer monsoon system is studied using a coupled atmosphere-slab ocean model. Our results suggest that anthropogenic and biomass burning aerosols generally induce a reduction in mean summer monsoon precipitation over most parts of the Indian subcontinent, strongest along the western coastline of the Indian peninsula and eastern Nepal region, but modest increases also occur over the north western part of the subcontinent. While most of the noted reduction in precipitation is triggered by increased emissions of aerosols from anthropogenic activities, modest increases in the north west are mostly associated with decreases in local emissions of aerosols from forest fire and grass fire sources. Anthropogenic aerosols from outside Asia also contribute to the overall reduction in precipitation but the dominant contribution comes from aerosol sources within Asia. Local emissions play a more important role in the total rainfall response to anthropogenic aerosol sources during the early monsoon period, whereas both local as well as remote emissions of aerosols play almost equally important roles during the later part of the monsoon period. While precipitation responses are primarily driven by local aerosol forcing, regional surface temperature changes over the region are strongly influenced by anthropogenic aerosols from sources further away (non-local changes). Changes in local anthropogenic organic and black carbon emissions by as much as a factor of two (preserving their ratio) produce the same basic signatures in the model's summer monsoon temperature and precipitation responses.

  5. Spatial and Temporal Variability of Outdoor Coarse Particulate Matter Mass Concentrations Measured with a New Coarse Particulate Sampler during the Detroit Exposure and Aerosol Research Study

    EPA Science Inventory

    The Detroit Exposure and Aerosol Research Study (DEARS) provided data to compare outdoor residential coarse particulate matter (PM10-2.5) concentrations in six different areas of Detroit with data from a central monitoring site. Daily and seasonal influences on the spa...

  6. INDOOR/OUTDOOR AEROSOL CONCENTRATION RATIOS DURING THE 1999 FRESNO PARTICULATE MATTER EXPOSURE STUDIES AS A FUNCTION OF SIZE, SEASON, AND TIME OF DAY

    EPA Science Inventory

    The 1999 Fresno particulate matter exposure studies tools place in February (winter season) and April/May (spring season) for two periods of four weeks. During that time, near-continuous measurements of indoor and outdoor aerosol concentrations were made with a scanning mobilit...

  7. Fast and Slow Responses of the South Asian Monsoon System to Anthropogenic Aerosols

    SciTech Connect

    Ganguly, Dilip; Rasch, Philip J.; Wang, Hailong; Yoon, Jin-Ho

    2012-09-25

    Using a global climate model with fully predictive aerosol life cycle, we investigate the fast and slow responses of the South Asian monsoon system to anthropogenic aerosol forcing. Our results show that the feedbacks associated with sea surface temperature (SST) change caused by aerosols play a more important role than the aerosol's direct impact on radiation, clouds and land surface (rapid adjustments) in shaping the total equilibrium climate response of the monsoon system to aerosol forcing. Inhomogeneous SST cooling caused by anthropogenic aerosols eventually reduces the meridional tropospheric temperature gradient and the easterly shear of zonal winds over the region, slowing down the local Hadley cell circulation, decreasing the northward moisture transport, and causing a reduction in precipitation over South Asia. Although total responses in precipitation are closer to the slow responses in general, the fast component dominates over land areas north of 25°N. Our results also show an east-west asymmetry in the fast responses to anthropogenic aerosols causing increases in precipitation west of 80°E but decreases east of it.

  8. The aerosol-monsoon climate system of Asia: A new paradigm

    NASA Astrophysics Data System (ADS)

    Lau, William K. M.

    2016-02-01

    This commentary is based on a series of recent lectures on aerosol-monsoon interactions I gave at the Beijing Normal University in August 2015. A main theme of the lectures is on a new paradigm of "An Aerosol-Monsoon-Climate-System", which posits that aerosol, like rainfall, cloud, and wind, is an integral component of the monsoon climate system, influencing monsoon weather and climate on all timescales. Here, salient issues discussed in my lectures and my personal perspective regarding interactions between atmospheric dynamics and aerosols from both natural and anthropogenic sources are summarized. My hope is that under this new paradigm, we can break down traditional disciplinary barriers, advance a deeper understanding of weather and climate in monsoon regions, as well as entrain a new generation of geoscientists to strive for a sustainable future for one of the most complex and challenging human-natural climate sub-system of the earth.

  9. Assessing a system to capture stray aerosol during inhalation of nebulized liposomal cisplatin.

    PubMed

    Wittgen, Bart P H; Kunst, Peter W A; Perkins, Walter R; Lee, Jin K; Postmus, Pieter E

    2006-01-01

    The aim of this study was to determine the efficacy of using a high-efficiency particulate air (HEPA) filter air cleaning system, a demistifier, to reduce the potential risk of fugitive aerosol contact in health care personnel working with patients inhaling nebulized liposomal encapsulated SLIT (Sustained-release Lipid Inhalation Targeting) Cisplatin. Filters were used to sample platinum in the air outside the tent and from the tent's exhaust stream. Air collection was performed under three conditions: (1) during patient dosing (14 h of air collection); (2) immediately after the patient has left the demistifier tent (4 h of air collection); and (3) when 7 mL of drug product was nebulized to dryness in the tent without a patient being present. Filters were collected, and placed in an extraction solvent. Subsequently, the solvent was assayed for platinum content by inductively coupled plasma-mass spectrometry (ICP-MS). Platinum levels in the extraction solvent were indistinguishable from the blank controls for all conditions. Measured levels were below workplace exposure limits established for cisplatin by the Occupational Safety and Health Administration (i.e., 2 ng . (L(1)). In addition, the demistifier was able to effectively capture aerosolized SLIT Cisplatin following nebulization of 7 mL of drug product to dryness in the tent. The demistifier tent is effective at containing any nebulized liposomal encapsulated cisplatin during patient treatment. Importantly, because the tent's HEPA filtration system is effective at removing any nebulized liposomal cisplatin, the exhausted air, which is free of platinum, can be returned into the room with no additional ventilation precautions. PMID:17034313

  10. Fate of inhaled monoclonal antibodies after the deposition of aerosolized particles in the respiratory system.

    PubMed

    Guilleminault, L; Azzopardi, N; Arnoult, C; Sobilo, J; Hervé, V; Montharu, J; Guillon, A; Andres, C; Herault, O; Le Pape, A; Diot, P; Lemarié, E; Paintaud, G; Gouilleux-Gruart, V; Heuzé-Vourc'h, N

    2014-12-28

    Monoclonal antibodies (mAbs) are usually delivered systemically, but only a small proportion of the drug reaches the lung after intravenous injection. The inhalation route is an attractive alternative for the local delivery of mAbs to treat lung diseases, potentially improving tissue concentration and exposure to the drug while limiting passage into the bloodstream and adverse effects. Several studies have shown that the delivery of mAbs or mAb-derived biopharmaceuticals via the airways is feasible and efficient, but little is known about the fate of inhaled mAbs after the deposition of aerosolized particles in the respiratory system. We used cetuximab, an anti-EGFR antibody, as our study model and showed that, after its delivery via the airways, this mAb accumulated rapidly in normal and cancerous tissues in the lung, at concentrations twice those achieved after intravenous delivery, for early time points. The spatial distribution of cetuximab within the tumor was heterogeneous, as reported after i.v. injection. Pharmacokinetic (PK) analyses were carried out in both mice and macaques and showed aerosolized cetuximab bioavailability to be lower and elimination times shorter in macaques than in mice. Using transgenic mice, we showed that FcRn, a key receptor involved in mAb distribution and PK, was likely to make a greater contribution to cetuximab recycling than to the transcytosis of this mAb in the airways. Our results indicate that the inhalation route is potentially useful for the treatment of both acute and chronic lung diseases, to boost and ensure the sustained accumulation of mAbs within the lungs, while limiting their passage into the bloodstream. PMID:25451545

  11. Remote Sensing of Aerosol Over the Land from the Earth Observing System MODIS Instrument

    NASA Technical Reports Server (NTRS)

    Kaufman, Yoram; Tanre, Didier; Remer, Lorraine; Einaudi, Franco (Technical Monitor)

    2000-01-01

    On Dec 18, 1999, NASA launched the Moderate-Resolution Imaging Spectroradiometer (MODIS) instrument on the Earth Observing System (EOS) Terra mission, in a spectacular launch. The mission will provide morning (10:30 AM) global observations of aerosol and other related parameters. It will be followed a year later by a MODIS instrument on EOS Aqua for afternoon observations (1:30 PM). MODIS will measure aerosol over land and ocean with its eight 500 m and 250 m channels in the solar spectrum (0-41 to 2.2 micrometers). Over the land MODIS will measure the total column aerosol loading, and distinguish between submicron pollution particles and large soil particles. Standard daily products of resolution of ten kilometers and global mapped eight day and monthly products on a 1x1 degree global scale will be produced routinely and make available for no or small reproduction charge to the international community. Though the aerosol products will not be available everywhere over the land, it is expected that they will be useful for assessments of the presence, sources and transport of urban pollution, biomass burning aerosol, and desert dust. Other measurements from MODIS will supplement the aerosol information, e.g., land use change, urbanization, presence and magnitude of biomass burning fires, and effect of aerosol on cloud microphysics. Other instruments on Terra, e.g. Multi-angle Imaging SpectroRadiometer (MISR) and the Clouds and the Earth's Radiant Energy System (CERES), will also measure aerosol, its properties and radiative forcing in tandem with the MODIS measurements. During the Aqua period, there are plans to launch in 2003 the Pathfinder Instruments for Cloud and Aerosol Spaceborne Observations (PICASSO) mission for global measurements of the aerosol vertical structure, and the PARASOL mission for aerosol characterization. Aqua-MODIS, PICASSO and PARASOL will fly in formation for detailed simultaneous characterization of the aerosol three-dimensional field, which

  12. A computer-controlled whole-body inhalation exposure system for the oil dispersant COREXIT EC9500A.

    PubMed

    Goldsmith, William Travis; McKinney, Walter; Jackson, Mark; Law, Brandon; Bledsoe, Toni; Siegel, Paul; Cumpston, Jared; Frazer, David

    2011-01-01

    An automated whole-body inhalation exposure system capable of exposing 12 individually housed rats was designed to examine the potential adverse health effects of the oil dispersant COREXIT EC9500A, used extensively during the Deepwater Horizon oil spill. A computer-controlled syringe pump injected the COREXIT EC9500A into an atomizer where droplets and vapor were formed and mixed with diluent air. The aerosolized COREXIT EC9500A was passed into a customized exposure chamber where a calibrated light-scattering instrument estimated the real-time particle mass concentration of the aerosol in the chamber. Software feedback loops controlled the chamber aerosol concentration and pressure throughout each exposure. The particle size distribution of the dispersant aerosol was measured and shown to have a count median aerodynamic diameter of 285 nm with a geometric standard deviation of 1.7. The total chamber concentration (particulate + vapor) was determined using a modification of the acidified methylene blue spectrophotometric assay for anionic surfactants. Tests were conducted to show the effectiveness of closed loop control of chamber concentration and to verify chamber concentration homogeneity. Five automated 5-h animal exposures were performed that produced controlled and consistent COREXIT EC9500A concentrations (27.1 ± 2.9 mg/m(3), mean ± SD).

  13. A COMPUTER-CONTROLLED WHOLE-BODY INHALATION EXPOSURE SYSTEM FOR THE OIL DISPERSANT COREXIT EC9500A

    PubMed Central

    Goldsmith, William Travis; McKinney, Walter; Jackson, Mark; Law, Brandon; Bledsoe, Toni; Siegel, Paul; Cumpston, Jared; Frazer, David

    2015-01-01

    An automated whole-body inhalation exposure system capable of exposing 12 individually housed rats was designed to examine the potential adverse health effects of the oil dispersant COREXIT EC9500A, used extensively during the Deepwater Horizon oil spill. A computer–controlled syringe pump injected the COREXIT EC9500A into an atomizer where droplets and vapor were formed and mixed with diluent air. The aerosolized COREXIT EC9500A was passed into a customized exposure chamber where a calibrated light-scattering instrument estimated the real-time particle mass concentration of the aerosol in the chamber. Software feedback loops controlled the chamber aerosol concentration and pressure throughout each exposure. The particle size distribution of the dispersant aerosol was measured and shown to have a count median aerodynamic diameter of 285 nm with a geometric standard deviation of 1.7. The total chamber concentration (particulate + vapor) was determined using a modification of the acidified methylene blue spectrophotometric assay for anionic surfactants. Tests were conducted to show the effectiveness of closed loop control of chamber concentration and to verify chamber concentration homogeneity. Five automated 5-h animal exposures were performed that produced controlled and consistent COREXIT EC9500A concentrations (27.1 ± 2.9 mg/m3, mean ± SD). PMID:21916743

  14. Addition of Tropospheric Chemistry and Aerosols to the NCAR Community Climate System Model

    SciTech Connect

    Cameron-Smith, P; Lamarque, J; Connell, P; Chuang, C; Rotman, D; Taylor, J

    2005-11-14

    Atmospheric chemistry and aerosols have several important roles in climate change. They affect the Earth's radiative balance directly: cooling the earth by scattering sunlight (aerosols) and warming the Earth by trapping the Earth's thermal radiation (methane, ozone, nitrous oxide, and CFCs are greenhouse gases). Atmospheric chemistry and aerosols also impact many other parts of the climate system: modifying cloud properties (aerosols can be cloud condensation nuclei), fertilizing the biosphere (nitrogen species and soil dust), and damaging the biosphere (acid rain and ozone damage). In order to understand and quantify the effects of atmospheric chemistry and aerosols on the climate and the biosphere in the future, it is necessary to incorporate atmospheric chemistry and aerosols into state-of-the-art climate system models. We have taken several important strides down that path. Working with the latest NCAR Community Climate System Model (CCSM), we have incorporated a state-of-the-art atmospheric chemistry model to simulate tropospheric ozone. Ozone is not just a greenhouse gas, it damages biological systems including lungs, tires, and crops. Ozone chemistry is also central to the oxidizing power of the atmosphere, which destroys a lot of pollutants in the atmosphere (which is a good thing). We have also implemented a fast chemical mechanism that has high fidelity with the full mechanism, for significantly reduced computational cost (to facilitate millennium scale simulations). Sulfate aerosols have a strong effect on climate by reflecting sunlight and modifying cloud properties. So in order to simulate the sulfur cycle more fully in CCSM simulations, we have linked the formation of sulfate aerosols to the oxidizing power of the atmosphere calculated by the ozone mechanisms, and to dimethyl sulfide emissions from the ocean ecosystem in the model. Since the impact of sulfate aerosols depends on the relative abundance of other aerosols in the atmosphere, we also

  15. Evaluation of Meteorological and Aerosol Sensing with small Unmanned Aerial Systems

    NASA Astrophysics Data System (ADS)

    Claussen, Johanna; Möhler, Ottmar; Leisner, Thomas; Brooks, Ian; Norris, Sarah; Brooks, Barbara; Hill, Martin; Haunold, Werner; Schrod, Jann; Danielczok, Anja

    2013-04-01

    Atmospheric aerosols have a large impact on the climate system due to their influence on the global radiation budget. Local aerosol sources such as vegetation, (bare) soil or industrial sites have to be quantified with high resolution data to validate aerosol transport models and improve the input for high resolution weather models. Our goal is to evaluate the use of Unmanned Aerial Systems (UAS) as a method for acquisition of high resolution meteorological and aerosol data. During the INUIT measurement campaign in August 2012 at mount Großer Feldberg near Frankfurt, Germany, several flights with different sensor packages were carried out. We measured basic meteorological parameters such as temperature, relative humidity and air pressure with miniaturized onboard sensors. In addition, the Compact Lightweight Aerosol Spectrometer Probe (CLASP) for aerosol size distribution measurement or the Electrostatic Aerosol Collector (EAC) for aerosol sample collection was installed on board. CLASP measures aerosol particles with diameters from 0.17 μm to 9.5 μm in up to 32 channels at a frequency of 10 Hz. The EAC collects air samples at 2 l/min onto a sample holder. After the flight the ice nuclei on the sample holder are activated and counted in the isothermal static diffusion chamber FRIDGE. The results from the INUIT campaign and additional calibration laboratory measurements show that UAS are a valuable platform for miniaturized sensors. The number of ice nuclei was determined with the EAC at 200m above ground level and compared to the reference measurement on the ground.

  16. Impact of Aerosols on Atmospheric Attenuation Loss in Central Receiver Systems: Preprint

    SciTech Connect

    Sengupta, M.; Wagner, M. J.

    2011-08-01

    Atmospheric attenuation loss between the heliostat field and receiver has been recognized as a significant source of loss in Central Receiver Systems. In clear sky situations, extinction of Direct Normal Irradiance (DNI) is primarily by aerosols in the atmosphere. When aerosol loading is high close to the surface the attenuation loss between heliostat and receivers is significantly influenced by the amount of aerosols present on a particular day. This study relates measured DNI to aerosol optical depths close to the surface of the earth. The model developed in the paper uses only measured DNI to estimate the attenuation between heliostat and receiver in a central receiver system. The requirement that only a DNI measurement is available potentially makes the model a candidate for widespread use.

  17. Current and Future Applications of the GEOS-5 Aerosol Modeling System

    NASA Technical Reports Server (NTRS)

    Colarco, Peter R.; Silva, Arlindo M Da; Burchard-Marchant, Virginie J.; Darmenov, Anton S.; Govindaraju, Ravi C.; Randles, Cynthia A.; Aquila, Valentina; Nowottnick, Edward Paul; Bian, Huisheng

    2013-01-01

    The presentation summarizes current and proposed activities for the GEOS-5 aerosol modeling system. Activities discussed include (i) forecasting and event simulation, (ii) observation simulation, (iii) aerosol-chemistry-climate applications, and (iv) future activities. The document was presented at the 2013 AEROCENTER Annual Meeting held at the GSFC Visitors Center May 31, 2013. The Organizers of the meeting are posting the talks to the public Aerocenter website, after the meeting.

  18. Stratospheric aerosol effects from Soufriere volcano as measured by the SAGE Satellite System

    SciTech Connect

    Mccormick, M.P.; Kent, G.S.; Yue, G.K.; Cunnold, D.M.

    1982-01-01

    During its April 1979 eruption series, soufriere volcano produced two major stratospheric plumes that the SAGE (Stratospheric Aerosol and Gas experiment) Satellite System tracked to West Africa and the North Atlantic Ocean. The total mass of these plumes, whose movement and dispersion are in agreement with those deduced from meteorological data and dispersion theory, was less than 0.5 percent of the global stratospheric aerosol burden; no significant temperature or climate perturbation is therefore expected.

  19. Aerosol Layering Characterization Near the Gobi Desert by a Double Polarization Lidar System

    NASA Astrophysics Data System (ADS)

    Zhao, Y.; Boselli, A.; Sannino, A.; Song, C.; Spinelli, N.; Wang, X.

    2016-06-01

    In order to carry out 4-D (space and time) analysis of the atmospheric aerosol distribution and to make a characterization of their properties and time evolution, a transportable multi-wavelength, Elastic/Raman scanning lidar system with angular scanning capability has been realized. The system uses a diode pumped Nd:YAG laser source, specifically designed for this device, and a receiving systems able to detect elastic signals at 355, 532 and 1064 nm and Raman signals at 386, 407 and 607 nm. It also allows to perform aerosol depolarization measurements at both 355nm and 532nm. A first measurement campaign has been carried out in Dunhuang, North-West of China, in the region of the Gobi desert with the aims to study and characterize desert dust at source. Optical properties of aerosol layers developing in the atmosphere have been analyzed and lidar data are discussed in terms of profiles of aerosol backscatter coefficient at 355nm, 532nm, aerosol extinction coefficient at 355nm, aerosol depolarization ratio at 355nm and 532nm and water vapor mixing ratio. Depolarization ratio measured simultaneously at two wavelengths allowed also to study its dependence on the wavelength.

  20. Inhalation toxicity study of disk-shaped potassium octatitanate particles (terracess TF) in rats following 90 days of aerosol exposure.

    PubMed

    Sakai, Seiya; Inada, Kousuke; Tanaka, Akira K; Kelly, David P; Sykes, Greg P; Lee, K P

    2010-01-01

    Since fibrous particles such as asbestos and some man-made fibers (MMF) have been known to produce carcinogenic or fibrogenic effects, disk-shaped potassium octatitanate (POT) particles (trade name: Terracess TF) were manufactured as nonfibrous particles. A 90-day inhalation toxicity study of Terracess TF was performed to evaluate comparative inhalation toxicity of the disk shape with a fibrous shape that was previously evaluated. Four groups of 20 male and 15 female rats each were exposed to Terracess TF aerosols at concentrations of 0, 2, 10, or 50 mg/m(3) for 90 days. Ten male and 10 female rats per group were sacrificed at 90 days of exposure. After 90 days of exposure, 5 male rats per group were sacrificed at 3 wk of recovery period and 4-5 male rats per group or 5 female rats per group were sacrificed at 15 wk of recovery for lung clearance and histopathology. The mass median aerodynamic equivalent diameter (MMAED) of the aerosols of test materials ranged from 2.5 to 2.9 microm. There were no test-substance-related adverse effects on clinical observations. At the end of the 90-day exposure, a slight increase in lung-to-body weight ratios was observed at 50 mg/m(3) in male but not in female rats. However, lung weights were within normal limits after 3- or 15-wk recovery periods. Microscopically, inhaled Terracess TF particles were mostly phagocytized by free alveolar macrophages (AMs) in the alveolar airspaces and alveolar walls maintained normal structure at 2 and 10 mg/m(3). At 50 mg/m(3), some alveoli were distended and filled with aggregates of particle-laden AMs. The alveolar walls showed slight type II pneumocyte hyperplasia, but neither proliferative inflammation nor alveolar fibrosis was present at 50 mg/m(3). The clearance half-times for Terracess TF were estimated to be in the order of 6 to 9 mo for the 50-mg/m(3) group and 2 to 3 mo for the 10- and 2-mg/m(3) groups. The lung responses and lung clearance rate were comparable to those of "nuisance

  1. Exposure to aerosolized bacteria and fungi among collectors of commercial, mixed residential, recyclable and compostable waste.

    PubMed

    Lavoie, Jacques; Dunkerley, Christopher J; Kosatsky, Tom; Dufresne, Andre

    2006-10-15

    Biological hazards associated with the collection of solid and compostable waste have not been well characterized in North America. This is an issue because workers who handle such materials may be exposed to bioaerosols (airborne bacteria and fungi) and dusts resulting in infections or allergic diseases. We conducted a personal sampling campaign for culturable bacteria and fungi in the breathing zones of waste collectors in a variety of typical work settings (scenarios) in the province of Quebec, Canada. Total culturable bacterial and fungal counts were analyzed and compared to ambient environmental levels (background) to determine the degree of incremental exposure among workers. In several scenarios, worker exposure counts were significantly (p < or = 0.05) higher than ambient levels measured upwind, with the highest personal exposures to bacteria observed for urban compostable waste collectors (median = 50,300 Colony Forming Units/m(3) of air (CFU/m(3))). On the other hand, fungal counts collected on an every-other-week cycle were highest among a group of rural compostable waste collectors (median = 101,700 CFU/m(3)). Similar exposures to culturable bacteria and fungi have been reported in European workers who showed such adverse health effects as nausea, diarrhea, upper respiratory tract irritation, and allergy. Therefore, it may be necessary to modify certain work practices in order to minimize exposure. Recommendations include automation of waste and compost collection, use of personal protective equipment including goggles, gloves, and disposable masks, and meticulous personal hygiene.

  2. CNR-IMAA lidar systems for aerosol, clouds, and water vapour study

    NASA Astrophysics Data System (ADS)

    Pappalardo, G.; Amodeo, A.; Boselli, A.; Cornacchia, C.; D'Amico, G.; Madonna, F.; Mona, L.; Pandolfi, M.

    2005-10-01

    At CNR-IMAA located in Tito Scalo (40°36'N, 15°44'E, 760 m a.s.l.), two lidar systems are systematically operational: the first is devoted to tropospheric aerosol characterization, in the framework of EARLINET, and the second performs water vapour measurements. The aerosol lidar system provides independent measurements of aerosol extinction and backscatter coefficient at 355 nm and at 532 nm, aerosol backscatter profiles at 1064 nm and particles depolarization ratio at 532 nm. The Raman lidar for the water vapor allows the vertical profiling of the water vapour mixing ratio with high spatial and temporal resolution up to the tropopause. The system has been calibrated by means of intensive measurement campaign of simultaneous and co-located radiosonde launches. CNR-IMAA is also provided with a DIAL mobile system for pollutants 3-dimensional spatial distribution. Besides these lidar systems, the CNR-IMAA ground based facility for Earth Observation includes ancillary instruments: a radiosounding system for PTU, ozone and wind measurements; a Sun photometer operative since December 2004 in the framework of AERONET; a 12 channels microwave radiometer for continuous measurements of temperature, relative humidity and water vapor, operative since February 2004; a ceilometer for continuous cloud cover monitoring. Lidar systems together with these ancillary instruments make the CNR-IMAA a heavily instrumented experimental site for integrated observations of aerosols, clouds and water vapor to be used for climatological studies and for the validation of satellite data.

  3. Occupational exposure to airborne nanomaterials: An assessment of worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fab and subfab.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2016-09-01

    support further statistical analysis and determine trends; however, this initial investigation suggests that nanoparticles used or generated by the wafer polishing process become aerosolized and may be accessible for inhalation exposures by workers performing tasks in the subfab and fab. Additional research is needed to further quantify the degree of exposure and link these findings to related hazard research.

  4. Occupational exposure to airborne nanomaterials: An assessment of worker exposure to aerosolized metal oxide nanoparticles in a semiconductor fab and subfab.

    PubMed

    Brenner, Sara A; Neu-Baker, Nicole M; Caglayan, Cihan; Zurbenko, Igor G

    2016-09-01

    support further statistical analysis and determine trends; however, this initial investigation suggests that nanoparticles used or generated by the wafer polishing process become aerosolized and may be accessible for inhalation exposures by workers performing tasks in the subfab and fab. Additional research is needed to further quantify the degree of exposure and link these findings to related hazard research. PMID:27135871

  5. High-Latitude Stratospheric Aerosols Measured by the SAM II Satellite System in 1978 and 1979.

    PubMed

    McCormick, M P; Chu, W P; Grams, G W; Hamill, P; Herman, B M; McMaster, L R; Pepin, T J; Russell, P B; Steele, H M; Swissler, T J

    1981-10-16

    Results of the first year of data collection by the SAM (Stratospheric Aerosol Measurement) II satellite system are presented. Almost 10,000 profiles of stratospheric aerosol extinction in the Arctic and Antarctic regions are used to construct plots of weekly averaged aerosol extinction versus altitude and time and stratospheric optical depth versus time. Corresponding temperature fields are presented. These data show striking similarities in the aerosol behavior for corresponding seasons. Wintertime polar stratospheric clouds that are strongly correlated with temperature are documented. They are much more prevalent in the Antarctic stratosphere during the cold austral winter and increase the stratospheric optical depths by as much as an order of magnitude for a period of about 2 months. These clouds might represent a sink for stratospheric water vapor and must be considered in the radiative budget for this region and time.

  6. Real-Time Detection Method And System For Identifying Individual Aerosol Particles

    DOEpatents

    Gard, Eric Evan; Fergenson, David Philip

    2005-10-25

    A method and system of identifying individual aerosol particles in real time. Sample aerosol particles are compared against and identified with substantially matching known particle types by producing positive and negative test spectra of an individual aerosol particle using a bipolar single particle mass spectrometer. Each test spectrum is compared to spectra of the same respective polarity in a database of predetermined positive and negative spectra for known particle types and a set of substantially matching spectra is obtained. Finally the identity of the individual aerosol particle is determined from the set of substantially matching spectra by determining a best matching one of the known particle types having both a substantially matching positive spectrum and a substantially matching negative spectrum associated with the best matching known particle type.

  7. High-latitude stratospheric aerosols measured by the SAM II satellite system in 1978 and 1979

    NASA Technical Reports Server (NTRS)

    Mccormick, M. P.; Chu, W. P.; Mcmaster, L. R.; Grams, G. W.; Hamill, P.; Steele, H. M.; Swissler, T. J.; Herman, B. M.; Pepin, T. J.; Russell, P. B.

    1981-01-01

    Results of the first year of data collection by the SAM (Stratospheric Aerosol Measurement) II satellite system are presented. Almost 10,000 profiles of stratospheric aerosol extinction in the Arctic and Antarctic regions are used to construct plots of weekly averaged aerosol extinction versus altitude and time and stratospheric optical depth versus time. Corresponding temperature fields are presented. These data show striking similarities in the aerosol behavior for corresponding seasons. Wintertime polar stratospheric clouds that are strongly correlated with temperature are documented. They are much more prevalent in the Antarctic stratosphere during the cold austral winter and increase the stratospheric optical depths by as much as an order of magnitude for a period of about 2 months. These clouds might represent a sink for stratospheric water vapor and must be considered in the radiative budget for this region and time.

  8. Pathological findings and diagnostic implications of a rhesus macaque (Macacca mulatta) model of aerosol exposure to Burkholderia mallei (glanders).

    PubMed

    Yingst, Samuel L; Facemire, Paul; Chuvala, Lara; Norwood, David; Wolcott, Mark; Huzella, Louis

    2015-06-01

    Burkholderia mallei is a Gram-negative bacillus that causes a pneumonic disease known as glanders in equids and humans, and a lymphatic infection known as farcy, primarily in equids. With the potential to infect humans by the respiratory route, aerosol exposure can result in severe, occasionally fatal, pneumonia. Today, glanders infections in humans are rare, likely due to less frequent contact with infected equids than in the past. Acutely ill humans often have non-specific clinical signs and in order to diagnose cases, especially in scenarios of multiple cases in an unexpected setting, rapid diagnostics for B. mallei may be critical. The pathogenesis of acute glanders in the rhesus macaque (Macaca mulatta) was studied as an initial effort to improve diagnostic methods. In the study described here, the diagnostic techniques of PCR, culture and histopathology were compared. The results indicated that PCR may provide rapid, non-invasive diagnosis of glanders in some cases. As expected, PCR results were positive in lung tissue in 11/12 acutely infected rhesus macaques, but more importantly in terms of diagnostic algorithm development, PCR results were frequently positive in non-invasive samples such as broncho-alveolar lavage or nasal swabs (7/12) and occasionally in blood (3/12). However, conventional bacterial culture failed to recover bacteria in many of these samples. The study showed that the clinical presentation of aerosol-exposed rhesus macaques is similar to descriptions of human glanders and that PCR has potential for rapid diagnosis of outbreaks, if not individual cases.

  9. Pathological findings and diagnostic implications of a rhesus macaque (Macacca mulatta) model of aerosol exposure to Burkholderia mallei (glanders)

    PubMed Central

    Yingst, Samuel L.; Chuvala, Lara; Norwood, David; Wolcott, Mark; Huzella, Louis

    2015-01-01

    Burkholderia mallei is a Gram-negative bacillus that causes a pneumonic disease known as glanders in equids and humans, and a lymphatic infection known as farcy, primarily in equids. With the potential to infect humans by the respiratory route, aerosol exposure can result in severe, occasionally fatal, pneumonia. Today, glanders infections in humans are rare, likely due to less frequent contact with infected equids than in the past. Acutely ill humans often have non-specific clinical signs and in order to diagnose cases, especially in scenarios of multiple cases in an unexpected setting, rapid diagnostics for B. mallei may be critical. The pathogenesis of acute glanders in the rhesus macaque (Macaca mulatta) was studied as an initial effort to improve diagnostic methods. In the study described here, the diagnostic techniques of PCR, culture and histopathology were compared. The results indicated that PCR may provide rapid, non-invasive diagnosis of glanders in some cases. As expected, PCR results were positive in lung tissue in 11/12 acutely infected rhesus macaques, but more importantly in terms of diagnostic algorithm development, PCR results were frequently positive in non-invasive samples such as broncho-alveolar lavage or nasal swabs (7/12) and occasionally in blood (3/12). However, conventional bacterial culture failed to recover bacteria in many of these samples. The study showed that the clinical presentation of aerosol-exposed rhesus macaques is similar to descriptions of human glanders and that PCR has potential for rapid diagnosis of outbreaks, if not individual cases. PMID:25850696

  10. Aerosol particles generated by diesel-powered school buses at urban schools as a source of children's exposure

    NASA Astrophysics Data System (ADS)

    Hochstetler, Heather A.; Yermakov, Mikhail; Reponen, Tiina; Ryan, Patrick H.; Grinshpun, Sergey A.

    2011-03-01

    Various heath effects in children have been associated with exposure to traffic-related particulate matter (PM), including emissions from school buses. In this study, the indoor and outdoor aerosol at four urban elementary schools serviced by diesel-powered school buses was characterized with respect to the particle number concentrations and size distributions as well as the PM2.5 mass concentrations and elemental compositions. It was determined that the presence of school buses significantly affected the outdoor particle size distribution, specifically in the ultrafine fraction. The time-weighted average of the total number concentration measured outside the schools was significantly associated with the bus and the car counts. The concentration increase was consistently observed during the morning drop-off hours and in most of the days during the afternoon pick-up period (although at a lower degree). Outdoor PM2.5 mass concentrations measured at schools ranged from 3.8 to 27.6 μg m-3. The school with the highest number of operating buses exhibited the highest average PM2.5 mass concentration. The outdoor mass concentrations of elemental carbon (EC) and organic carbon (OC) were also highest at the school with the greatest number of buses. Most (47/55) correlations between traffic-related elements identified in the outdoor PM2.5 were significant with elements identified in the indoor PM2.5. Significant associations were observed between indoor and outdoor aerosols for EC, EC/OC, and the total particle number concentration. Day-to-day and school-to-school variations in Indoor/Outdoor (I/O) ratios were related to the observed differences in opening windows and doors, which enhanced the particle penetration, as well as indoor activities at schools. Overall, the results on I/O ratio obtained in this study reflect the sizes of particles emitted by diesel-powered school bus engines (primarily, an ultrafine fraction capable of penetrating indoors).

  11. Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system.

    PubMed

    Seinfeld, John H; Bretherton, Christopher; Carslaw, Kenneth S; Coe, Hugh; DeMott, Paul J; Dunlea, Edward J; Feingold, Graham; Ghan, Steven; Guenther, Alex B; Kahn, Ralph; Kraucunas, Ian; Kreidenweis, Sonia M; Molina, Mario J; Nenes, Athanasios; Penner, Joyce E; Prather, Kimberly A; Ramanathan, V; Ramaswamy, Venkatachalam; Rasch, Philip J; Ravishankara, A R; Rosenfeld, Daniel; Stephens, Graeme; Wood, Robert

    2016-05-24

    The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty.

  12. Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system.

    PubMed

    Seinfeld, John H; Bretherton, Christopher; Carslaw, Kenneth S; Coe, Hugh; DeMott, Paul J; Dunlea, Edward J; Feingold, Graham; Ghan, Steven; Guenther, Alex B; Kahn, Ralph; Kraucunas, Ian; Kreidenweis, Sonia M; Molina, Mario J; Nenes, Athanasios; Penner, Joyce E; Prather, Kimberly A; Ramanathan, V; Ramaswamy, Venkatachalam; Rasch, Philip J; Ravishankara, A R; Rosenfeld, Daniel; Stephens, Graeme; Wood, Robert

    2016-05-24

    The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty. PMID:27222566

  13. Lidar System for Airborne Measurement of Clouds and Aerosols

    NASA Technical Reports Server (NTRS)

    McGill, Matthew; Scott, V. Stanley; Izquierdo, Luis Ramos; Marzouk, Joe

    2008-01-01

    A lidar system for measuring optical properties of clouds and aerosols at three wavelengths is depicted. The laser transmitter is based on a Nd:YVO4 laser crystal pumped by light coupled to the crystal via optical fibers from laser diodes that are located away from the crystal to aid in dissipating the heat generated in the diodes and their drive circuits. The output of the Nd:YVO4 crystal has a wavelength of 1064 nm, and is made to pass through frequency-doubling and frequency-tripling crystals. As a result, the net laser output is a collinear superposition of beams at wavelengths of 1064, 532, and 355 nm. The laser operates at a pulse-repetition rate of 5 kHz, emitting per-pulse energies of 50 microJ at 1064 nm, 25 microJ at 532 nm and 50 microJ at 355 nm. An important feature of this system is an integrating sphere located between the laser output and the laser beam expander lenses. The integrating sphere collects light scattered from the lenses. Three energy-monitor detectors are located at ports inside the integrating sphere. Each of these detectors is equipped with filters such that the laser output energy is measured independently for each wavelength. The laser output energy is measured on each pulse to enable the most accurate calibration possible. The 1064-nm and 532-nm photodetectors are, more specifically, single photon-counting modules (SPCMs). When used at 1064 nm, these detectors have approximately 3% quantum efficiency and low thermal noise (fewer than 200 counts per second). When used at 532 nm, the SPCMs have quantum efficiency of about 60%. The photodetector for the 355-nm channel is a photon-counting photomultiplier tube having a quantum efficiency of about 20%. The use of photon-counting detectors is made feasible by the low laser pulse energy. The main advantage of photon-counting is ease of inversion of data without need for complicated calibration schemes like those necessary for analog detectors. The disadvantage of photon-counting detectors

  14. Exposure and Emissions Monitoring during Carbon Nanofiber Production—Part I: Elemental Carbon and Iron–Soot Aerosols

    PubMed Central

    Birch, M. Eileen; Ku, Bon-Ki; Evans, Douglas E.; Ruda-Eberenz, Toni A.

    2015-01-01

    Production of carbon nanofibers and nanotubes (CNFs/CNTs) and their composite products is increasing globally. High volume production may increase the exposure risks for workers who handle these materials. Though health effects data for CNFs/CNTs are limited, some studies raise serious health concerns. Given the uncertainty about their potential hazards, there is an immediate need for toxicity data and field studies to assess exposure to CNFs/CNTs. An extensive study was conducted at a facility that manufactures and processes CNFs. Filter, sorbent, cascade impactor, bulk, and microscopy samples, combined with direct-reading instruments, provided complementary information on air contaminants. Samples were analyzed for organic carbon (OC) and elemental carbon (EC), metals, and polycyclic aromatic hydrocarbons (PAHs), with EC as a measure of CNFs. Transmission electron microscopy with energy-dispersive X-ray spectroscopy also was applied. Fine/ultrafine iron-rich soot, PAHs, and carbon monoxide were production byproducts. Direct-reading instrument results were reported previously [Evans DE et al. (Aerosol monitoring during carbon nanofiber production: mobile direct-reading sampling. Ann Occup Hyg 2010;54:514–31.)] Results for time-integrated samples are reported as companion papers in this Issue. OC and EC, metals, and microscopy results are reported here, in Part I, while results for PAHs are reported in Part II [Birch ME. (Exposure and Emissions Monitoring during Carbon Nanofiber Production—Part II: Polycyclic Aromatic Hydrocarbons. Ann. Occup. Hyg 2011; 55: 1037–47.)]. Respirable EC area concentrations inside the facility were about 6–68 times higher than outdoors, while personal breathing zone samples were up to 170 times higher. PMID:21965464

  15. CHARACTERIZATION OF INDOOR-OUTDOOR AEROSOL CONCENTRATION RELATIONSHIPS DURING THE FRESNO PM EXPOSURE STUDIES

    EPA Science Inventory

    Particle size distributions were measured indoors and outdoors of a single, detached residence during the Fresno particulate matter exposure studies in winter (February 1-28, 1999) and spring (April 18-May 16, 1999). Data was collected for particle sizes ranging from about 0....

  16. Comet assay and air-liquid interface exposure system: a new combination to evaluate genotoxic effects of cigarette whole smoke in human lung cell lines.

    PubMed

    Weber, Susanne; Hebestreit, Marco; Wilms, Torsten; Conroy, Lynda L; Rodrigo, Gregory

    2013-09-01

    Over the past three decades, the genotoxic effects of cigarette smoke have generally been evaluated in non-human cell models after exposure to particulate phase, gas phase, or cigarette smoke condensate, rather than the whole smoke aerosol itself. In vitro setups using human cell lines and whole smoke exposure to mimic actual aerosol exposure should more accurately reflect human cigarette smoke exposure. We investigated the VITROCELL® 24 air-liquid interface exposure system in combination with the comet assay to assess DNA damage in two different human lung epithelial cell lines exposed to whole smoke. Results showed a repeatable and reproducible dose-response relationship between DNA damage and increased whole smoke dose in both cell lines. Thus, the combination of the comet assay with the VITROCELL® 24 represents a valuable new in vitro test system to screen and assess DNA damage in human lung cells exposed to whole smoke.

  17. GNI - A System for the Impaction and Automated Optical Sizing of Giant Aerosol Particles with Emphasis on Sea Salt

    NASA Astrophysics Data System (ADS)

    Jensen, Jorgen

    2013-04-01

    Size distributions of giant aerosol particles (e.g. sea-salt particles, dry radius larger than 0.5 μm) are not well characterized in the atmosphere, yet they contribute greatly to both direct and indirect aerosol effects. Measurements are problematic for these particles because they (i) occur in low concentrations, (ii) have difficulty in passing through air inlets, (iii) there are problems in discriminating between dry and deliquesced particles, (iv) and impaction sampling requires labor intensive methods. In this study, a simple, high-volume impaction system called the Giant Nuclei Impactor (GNI), based on free-stream exposure of polycarbonate slides from aircraft is described, along with an automated optical microscope-based system for analysis of the impacted particles. The impaction slides are analyzed in a humidity-controlled box (typically 90% relative humidity) that allows for deliquescence of sea salt particles. A computer controlled optical microscope with two digital cameras is used to acquire and analyze images of the aerosol particles. Salt particles will form near-spherical cap solution drops at high relative humidity. The salt mass in each giant aerosol particle is then calculated using simple geometry and K ̈ohler theory by assuming a NaCl composition. The system has a sample volume of about 10 L/s at aircraft speeds of 105 m/s. For salt particles, the measurement range is from about 0.7 μm dry radius to tens of micrometers, with a size-bin resolution of 0.2 μm dry radius. The sizing accuracy was tested using glass beads of known size. Characterizing the uncertainties of observational data is critical for applications to atmospheric science studies. A comprehensive uncertainty analysis is performed for the airborne GNI manual impaction and automatic optical microscope system for sizing giant aerosol particles, with particular emphasis on sea-salt particles. The factors included are (i) sizing accuracy, (ii) concentration accuracy, (iii

  18. Uncertainty in Cloud Aerosol Transport System (CATS) Doppler Lidar Products and Measurements

    NASA Astrophysics Data System (ADS)

    Selmer, P. A.

    2010-12-01

    The Cloud Aerosol Transport System (CATS) is both a high spectral resolution lidar and Doppler lidar currently being developed at NASA Goddard Space Flight Center for use as a demonstrator instrument for NASA’s Aerosol Cloud Ecosystem (ACE) Mission. CATS is intended to fly on NASA’s high-altitude ER-2 aircraft. CATS will be capable of measuring both aerosol properties and horizontal wind velocity as a function of altitude. The accuracy of these measurements is important to the success of the instrument and the ACE mission. Uncertainty equations for both the aerosol and wind products are derived. Initially the only sources of error are assumed to be instrument error in the spectral measurements. Using simulated CATS spectral measurements from simulated atmospheric profiles (an atmosphere with only a cirrus layer, an atmosphere with only a cumulus layer, an atmosphere with only an aerosol layer, and an atmosphere with no clouds or aerosols), the uncertainty in the aerosol and wind products are calculated. These calculated uncertainties are found to be within reason. Also worthy of consideration is the effect of aircraft motion on CATS’ wind measurements and products. An equation for the the nadir angle (assumed to be about 45 degrees for CATS), as well as the uncertainty in this angle, in terms of aircraft pitch and roll is derived. The effect of uncertainty in this angle on the uncertainty in CATS aerosol and wind products is calculated using the same simulated data previously mentioned, which is found to be insignificant for normal, steady flight.

  19. Application of Aerosol Assimilation System of MODIS Radiances to Regional Chemical Transport Model

    NASA Astrophysics Data System (ADS)

    D'Allura, A.; Charmichael, G. R.; Tang, Y.; Chai, T.; Chung, C. E.; Anderson, T. L.

    2006-12-01

    We present results from an assimilation system of radiances from the MODIS channels that sense atmospheric aerosols over land and ocean on the chemical transport model STEM. A test case is designed to simulate transport of aerosols tracers over the area of interest which includes India, east and south Asia at 50km horizontal resolution. A detailed treatment of the source, transport and deposition of the aerosol species are included. The model simulates five aerosol components: sulfate, organic carbon, black carbon, dust and sea salt. Total AODs at 550nm wavelength over land and ocean and fine mode AODs at 550nm wavelength over ocean are the level 2 aerosol products from Terra MODIS channel four used in this application. The intent of the study is to verify the improvement in the model performances while the initial conditions are corrected using an Optimum Interpolation technique to assimilate the MODIS data. The model results are compared with ground-based measurements of aerosol optical depth (AOD) from the AERONET network. Sensitivity analyses are provided in order to describe the effect of changing in assimilation technique's free parameters. The method is designed to optimize the use of the information provided by fine mode AODs, which are available over ocean, coupled with the total AODs available also over land. Improvements on the model results using this approach are highlighted during specific event where the model has experienced low agreement with observed data. Results are also compared to other assimilations methods.

  20. Dual-aureole and sun spectrometer system for airborne measurements of aerosol optical properties.

    PubMed

    Zieger, Paul; Ruhtz, Thomas; Preusker, Rene; Fischer, Jürgen

    2007-12-10

    We have designed an airborne spectrometer system for the simultaneous measurement of the direct sun irradiance and the aureole radiance in two different solid angles. The high-resolution spectral radiation measurements are used to derive vertical profiles of aerosol optical properties. Combined measurements in two solid angles provide better information about the aerosol type without additional and elaborate measuring geometries. It is even possible to discriminate between absorbing and nonabsorbing aerosol types. Furthermore, they allow to apply additional calibration methods and simplify the detection of contaminated data (e.g., by thin cirrus clouds). For the characterization of the detected aerosol type a new index is introduced that is the slope of the aerosol phase function in the forward scattering region. The instrumentation is a flexible modular setup, which has already been successfully applied in airborne and ground-based field campaigns. We describe the setup as well as the calibration of the instrument. In addition, example vertical profiles of aerosol optical properties--including the aureole measurements--are shown and discussed.

  1. Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.

    PubMed

    Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H

    2016-02-01

    High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking. PMID:26730457

  2. Characterization of a Quadrotor Unmanned Aircraft System for Aerosol-Particle-Concentration Measurements.

    PubMed

    Brady, James M; Stokes, M Dale; Bonnardel, Jim; Bertram, Timothy H

    2016-02-01

    High-spatial-resolution, near-surface vertical profiling of atmospheric chemical composition is currently limited by the availability of experimental platforms that can sample in constrained environments. As a result, measurements of near-surface gradients in trace gas and aerosol particle concentrations have been limited to studies conducted from fixed location towers or tethered balloons. Here, we explore the utility of a quadrotor unmanned aircraft system (UAS) as a sampling platform to measure vertical and horizontal concentration gradients of trace gases and aerosol particles at high spatial resolution (1 m) within the mixed layer (0-100 m). A 3D Robotics Iris+ autonomous quadrotor UAS was outfitted with a sensor package consisting of a two-channel aerosol optical particle counter and a CO2 sensor. The UAS demonstrated high precision in both vertical (±0.5 m) and horizontal positions (±1 m), highlighting the potential utility of quadrotor UAS drones for aerosol- and trace-gas measurements within complex terrain, such as the urban environment, forest canopies, and above difficult-to-access areas such as breaking surf. Vertical profiles of aerosol particle number concentrations, acquired from flights conducted along the California coastline, were used to constrain sea-spray aerosol-emission rates from coastal wave breaking.

  3. Systems biology of human benzene exposure

    PubMed Central

    Zhang, Luoping; McHale, Cliona M.; Rothman, Nathaniel; Li, Guilan; Ji, Zhiying; Vermeulen, Roel; Hubbard, Alan E.; Ren, Xuefeng; Shen, Min; Rappaport, Stephen M.; North, Matthew; Skibola, Christine F.; Yin, Songnian; Vulpe, Christopher; Chanock, Stephen J.; Smith, Martyn T.; Lan, Qing

    2010-01-01

    Toxicogenomic studies, including genome-wide analyses of susceptibility genes (genomics), gene expression (transcriptomics), protein expression (proteomics), and epigenetic modifications (epigenomics), of human populations exposed to benzene are crucial to understanding gene-environment interactions, providing the ability to develop biomarkers of exposure, early effect and susceptibility. Comprehensive analysis of these toxicogenomic and epigenomic profiles by bioinformatics in the context of phenotypic endpoints, comprises systems biology, which has the potential to comprehensively define the mechanisms by which benzene causes leukemia. We have applied this approach to a molecular epidemiology study of workers exposed to benzene. Hematotoxicity, a significant decrease in almost all blood cell counts, was identified as a phenotypic effect of benzene that occurred even below 1ppm benzene exposure. We found a significant decrease in the formation of progenitor colonies arising from bone marrow stem cells with increasing benzene exposure, showing that progenitor cells are more sensitive to the effects of benzene than mature blood cells, likely leading to the observed hematotoxicity. Analysis of transcriptomics by microarray in the peripheral blood mononuclear cells of exposed workers, identified genes and pathways (apoptosis, immune response, and inflammatory response) altered at high (>10ppm) and low (<1ppm) benzene levels. Serum proteomics by SELDI-TOF-MS revealed proteins consistently down-regulated in exposed workers. Preliminary epigenomics data showed effects of benzene on the DNA methylation of specific genes. Genomic screens for candidate genes involved in susceptibility to benzene toxicity are being undertaken in yeast, with subsequent confirmation by RNAi in human cells, to expand upon the findings from candidate gene analyses. Data on these and future biomarkers will be used to populate a large toxicogenomics database, to which we will apply bioinformatic

  4. Code System to Calculate Particle Penetration Through Aerosol Transport Lines.

    1999-07-14

    Version 00 Distribution is restricted to US Government Agencies and Their Contractors Only. DEPOSITION1.03 is an interactive software program which was developed for the design and analysis of aerosol transport lines. Models are presented for calculating aerosol particle penetration through straight tubes of arbitrary orientation, inlets, and elbows. An expression to calculate effective depositional velocities of particles on tube walls is derived. The concept of maximum penetration is introduced, which is the maximum possible penetrationmore » through a sampling line connecting any two points in a three-dimensional space. A procedure to predict optimum tube diameter for an existing transport line is developed. Note that there is a discrepancy in this package which includes the DEPOSITION 1.03 executable and the DEPOSITION 2.0 report. RSICC was unable to obtain other executables or reports.« less

  5. Studies of Ice Nucleating Aerosol Particles in Arctic Cloud Systems

    NASA Technical Reports Server (NTRS)

    Rogers, David C.; DeMott, Paul J.; Kreidenweis, Sonia M.

    2001-01-01

    The focus of this research is to improve the understanding of ice nucleating aerosol particles (IN) and the role they play in ice formation in Arctic clouds. IN are important for global climate issues in a variety of ways. The primary effect is their role in determining the phase (liquid or solid) of cloud particles. The microscale impact is on cloud particle size, growth rate, shape, fall speed, concentration, radiative properties, and scavenging of gases and aerosols. On a larger scale, ice formation affects the development of precipitation (rate, amount, type, and distribution), latent heat release (rate and altitude), ambient humidity, the persistence of clouds, and cloud albedo. The overall goals of our FIRE 3 research are to characterize the concentrations and variability of Arctic IN during the winter-spring transition, to compare IN measurements with ice concentrations in Arctic clouds, and to examine selected IN samples for particle morphology and chemical there are distinguishable chemical signatures. The results can be combined with other measurements of aerosols, gaseous species, and cloud characteristics in order to understand the processes that determine the phase and concentration of cloud particles.

  6. New liquid aerosol generation devices: systems that force pressurized liquids through nozzles.

    PubMed

    Geller, David E

    2002-12-01

    Over the past few decades, aerosol delivery devices have been relatively inefficient, wasteful, and difficult for patients to use. These drawbacks have been tolerated because the drugs available for inhalation have wide therapeutic margins and steep dose-response curves at low doses. Recently several forces have converged to drive innovation in the aerosol device industry: the ban on chlorofluorocarbon propellants in metered-dose inhalers, the need for more user-friendly devices, and the invention of expensive inhalable therapies for topical and systemic lung delivery. Numerous devices are in development to improve the efficiency, ease of use, and reproducibility of aerosol delivery to the lung, including systems that force liquid through a nozzle to form the aerosol cloud. The Respimat is a novel, compact, propellant-free, multi-dose inhaler that employs a spring to push drug solution through a nozzle, which generates a slow-moving aerosol. Deposition studies show that the Respimat can deliver 39-44% of a dose to the lungs. Clinical asthma and chronic obstructive pulmonary disease trials with bronchodilators show that the Respimat is 2-8 times as effective as a metered-dose inhaler. Respimat has been tested with bronchodilators and inhaled corticosteroids. The AERx device uses sophisticated electronics to deliver aerosol from a single-dose blister, using an integral, disposable nozzle array. The electronics control dose expression and titration, timing of aerosol generation with the breath, and provide feedback for proper inhalation technique. Lung deposition ranges from 50 to 80% of the loaded dose, with remarkable reproducibility. AERx has been tested with a variety of drugs, for both topical and systemic delivery, including rhDNase (dornase alfa), insulin, and opioids. These novel devices face competition from other technologies as well as financial and regulatory hurdles, but they both offer a marked improvement in the efficiency of pulmonary drug delivery.

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

    PubMed Central

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

    2016-01-01

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

  8. Evaluation of exposure to water aerosol or air by nose-only or whole-body inhalation procedures for CD-1 mice in developmental toxicity studies.

    PubMed

    Tyl, R W; Ballantyne, B; Fisher, L C; Fait, D L; Savine, T A; Pritts, I M; Dodd, D E

    1994-08-01

    This study was performed to evaluate the effects of nose-only restraint versus whole-body exposure procedures in the absence of test chemical, and to determine the appropriate control environment (water aerosol or air) for subsequent developmental toxicity studies of test materials administered as aerosols. Timed-pregnant CD-1 mice, 30/group, were exposed to high concentrations of water aerosol or to air by whole-body or nose-only inhalation procedures on Gestational Days (GD) 6 through 15 for 6 hr per day. The group exposed to air by whole-body procedures was designated as the control group. Clinical observations and maternal body weights were recorded throughout gestation. At scheduled necropsy on GD 18, maternal animals were evaluated for body weight, gravid uterine weight, liver weight, number of ovarian corpora lutea, and status of uterine implantation sites. Fetuses were counted, weighed, and sexed and were examined for external, visceral (including craniofacial), and skeletal alterations. Indices of maternal toxicity were affected in both nose-only groups. Maternal body weights were reduced during and after the exposure period; maternal weight gain was reduced during the exposure period. Clinical signs observed, from animals struggling during restraint, were resolved by GD 18. At sacrifice on GD 18, maternal body weights and maternal gestational weight gains (both corrected for gravid uterine weights) and absolute liver weights were reduced in both nose-only groups. Four females died (13.3%, all pregnant) in the air nose-only group, and maternal liver weight (relative to body weight) was reduced in the aerosol nose-only group. Gestational parameters were unaffected by any of the treatments. There were no statistically significant differences in the incidences of any individual malformations or malformations by category (external, visceral, or skeletal) or of total malformations. However, exencephaly, low set ears, cleft palate and ventricular septal defect

  9. Florida red tide and human health: a pilot beach conditions reporting system to minimize human exposure.

    PubMed

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-08-25

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While many of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida's west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting pathway for

  10. Florida red tide and human health: a pilot beach conditions reporting system to minimize human exposure.

    PubMed

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-08-25

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While many of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida's west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting pathway for

  11. Florida Red Tide and Human Health: A Pilot Beach Conditions Reporting System to Minimize Human Exposure

    PubMed Central

    Kirkpatrick, Barbara; Currier, Robert; Nierenberg, Kate; Reich, Andrew; Backer, Lorraine C.; Stumpf, Richard; Fleming, Lora; Kirkpatrick, Gary

    2008-01-01

    With over 50% of the US population living in coastal counties, the ocean and coastal environments have substantial impacts on coastal communities. While may of the impacts are positive, such as tourism and recreation opportunities, there are also negative impacts, such as exposure to harmful algal blooms (HABs) and water borne pathogens. Recent advances in environmental monitoring and weather prediction may allow us to forecast these potential adverse effects and thus mitigate the negative impact from coastal environmental threats. One example of the need to mitigate adverse environmental impacts occurs on Florida’s west coast, which experiences annual blooms, or periods of exuberant growth, of the toxic dinoflagellate, Karenia brevis. K. brevis produces a suite of potent neurotoxins called brevetoxins. Wind and wave action can break up the cells, releasing toxin that can then become part of the marine aerosol or sea spray. Brevetoxins in the aerosol cause respiratory irritation in people who inhale it. In addition, asthmatics who inhale the toxins report increase upper and lower airway lower symptoms and experience measurable changes in pulmonary function. Real-time reporting of the presence or absence of these toxic aerosols will allow asthmatics and local coastal residents to make informed decisions about their personal exposures, thus adding to their quality of life. A system to protect public health that combines information collected by an Integrated Ocean Observing System (IOOS) has been designed and implemented in Sarasota and Manatee Counties, Florida. This system is based on real-time reports from lifeguards at the eight public beaches. The lifeguards provide periodic subjective reports of the amount of dead fish on the beach, apparent level of respiratory irritation among beach-goers, water color, wind direction, surf condition, and the beach warning flag they are flying. A key component in the design of the observing system was an easy reporting

  12. Clinical assessment of a commercial aerosol delivery system for ventilation scanning by comparison with KR-81m

    SciTech Connect

    Wollmer, P.; Eriksson, L.; Andersson, A.C.

    1984-01-01

    Radioactive aerosols offer a means for steady state ventilation scanning in multiple views. The clinical use of radioaerosol techniques has been hampered by the lack of delivery systems producing sufficiently small particles. If the aerosol contains large particles, heavy deposition occurs in major airways, especially in patients with airways disease. The authors have assessed a new, commercial aerosol delivery system (Syntevent) by comparison with Kr-81m ventilation scanning in 23 patients with airways obstruction. An indirect comparison was also made with a settling bad technique. Ventilation scans in four projections were obtained during continuous inhalation of Kr-81m. Subsequently, the patient inhaled an aerosol labelled with In-113m from the Syntevent system, and aerosol ventilation scans were obtained in the same projections. Spirometry was performed to establish the degree of airways obstruction. The aerosol delineated the ventilated regions of the lungs adequately in all the patients. Deposition of aerosol in larger airways was seen in a few patients only, and this did not impede the interpretation of the scintigram. A quantitative analysis of the penetration of the aerosol to the periphery of the lung failed to demonstrate any significant correlation between particle penetration and airways obstruction. Aerosol penetration was significantly greater (p<0.001) with the Syntevent system than with a settling bag technique.

  13. Source term experiments project (STEP): aerosol characterization system

    SciTech Connect

    Schlenger, B.J.; Dunn, P.F.

    1985-01-01

    A series of four experiments is being conducted at Argonne National Laboratory's TREAT Reactor. They have been designed to provide some of the necessary data regarding magnitude and release rates of fission products from degraded fuel pins, physical and chemical characteristics of released fission products, and aerosol formation and transport phenomena. These are in-pile experiments, whereby the test fuel is heated by neutron induced fission and subsequent clad oxidation in steam environments that simulate as closely as practical predicted reactor accident conditions. The test sequences cover a range of pressure and fuel heatup rate, and include the effect of Ag/In/Cd control rod material.

  14. Green job bio-aerosol exposure during anaerobic digestion for biomass energetic valorisation.

    PubMed

    Traversi, Deborah; Gorrasi, Ilaria; Bonetta, Sara; Leinardi, Riccardo; Pietrangeli, Biancamaria; Carraro, Elisabetta; Gilli, Giorgio

    2015-04-01

    The continued expansion of the green economy increases the risk profile for green occupational jobs. One of the broadest green sectors in terms of growth is the anaerobic digestion of biomasses. In recent years, this development has also interested Italian regions. The management of biomass includes biological risk and the risk of particulate and endotoxin exposure. In the present study, we evaluated airborne exposure for anaerobic digestion workers at two real-scale plants. Digested biomass has different origins, ranging from cattle sludge and manure to poultry manure to agricultural harvesting or processing residues, particularly from maize and fruits. Two sampling points were chosen: at the first, the input biomasses were stored, and the hopper was loaded; at the second, the digested sludge exited the digester. The microbiological parameters, assessed using an active sampler and cultural method, were the total bacteria counts (at 22, 37, and 55°C), yeasts, fungi, Pseudomonaceae, Clostridia spp., Enterobacteriaceae and Actinomycetes. Moreover, at the same sampling points, we evaluated six PM10 fraction levels (10.0-7.2, 7.2-3.0, 3.0-1.5, 1.5-0.95, 0.95-0.49, and <0.49µm) and the endotoxin content of each fraction. In this investigation, the microbe contamination of the air varied from low to high levels, while the PM10 and endotoxin levels were limited, reaching rural environmental levels (61.40µg/m(3) and 18.88EU/m(3), respectively). However, contamination and occupational risk must be evaluated individually for each plant because numerous variables influence the risk magnitude, particularly digested sludge treatments, such as input biomass nature, storage, movement conditions, building configuration and technological processes.

  15. Magnetic field exposure and behavioral monitoring system.

    PubMed

    Thomas, A W; Drost, D J; Prato, F S

    2001-09-01

    To maximize the availability and usefulness of a small magnetic field exposure laboratory, we designed a magnetic field exposure system that has been used to test human subjects, caged or confined animals, and cell cultures. The magnetic field exposure system consists of three orthogonal pairs of coils 2 m square x 1 m separation, 1.751 m x 0.875 m separation, and 1.5 m x 0.75 m separation. Each coil consisted of ten turns of insulated 8 gauge stranded copper conductor. Each of the pairs were driven by a constant-current amplifier via digital to analog (D/A) converter. A 9 pole zero-gain active Bessel low-pass filter (1 kHz corner frequency) before the amplifier input attenuated the expected high frequencies generated by the D/A conversion. The magnetic field was monitored with a 3D fluxgate magnetometer (0-3 kHz, +/- 1 mT) through an analog to digital converter. Behavioral monitoring utilized two monochrome video cameras (viewing the coil center vertically and horizontally), both of which could be video recorded and real-time digitally Moving Picture Experts Group (MPEG) encoded to CD-ROM. Human postural sway (standing balance) was monitored with a 3D forceplate mounted on the floor, connected to an analog to digital converter. Lighting was provided by 12 offset overhead dimmable fluorescent track lights and monitored using a digitally connected spectroradiometer. The dc resistance, inductance of each coil pair connected in series were 1.5 m coil (0.27 Omega, 1.2 mH), 1.75 m coil (0.32 Omega, 1.4 mH), and 2 m coil (0.38 Omega, 1.6 mH). The frequency response of the 1.5 m coil set was 500 Hz at +/- 463 microT, 1 kHz at +/- 232 microT, 150 micros rise time from -200 microT(pk) to + 200 microT(pk) (square wave) and is limited by the maximum voltage ( +/- 146 V) of the amplifier (Bessel filter bypassed). PMID:11536281

  16. Experimental Technique for Studying Aerosols of Lyophilized Bacteria

    PubMed Central

    Cox, Christopher S.; Derr, John S.; Flurie, Eugene G.; Roderick, Roger C.

    1970-01-01

    An experimental technique is presented for studying aerosols generated from lyophilized bacteria by using Escherichia coli B, Bacillus subtilis var. niger, Enterobacter aerogenes, and Pasteurella tularensis. An aerosol generator capable of creating fine particle aerosols of small quantities (10 mg) of lyophilized powder under controlled conditions of exposure to the atmosphere is described. The physical properties of the aerosols are investigated as to the distribution of number of aerosol particles with particle size as well as to the distribution of number of bacteria with particle size. Biologically unstable vegetative cells were quantitated physically by using 14C and Europium chelate stain as tracers, whereas the stable heat-shocked B. subtilis spores were assayed biologically. The physical persistence of the lyophilized B. subtilis aerosol is investigated as a function of size of spore-containing particles. The experimental result that physical persistence of the aerosol in a closed aerosol chamber increases as particle size is decreased is satisfactorily explained on the bases of electrostatic, gravitational, inertial, and diffusion forces operating to remove particles from the particular aerosol system. The net effect of these various forces is to provide, after a short time interval in the system (about 2 min), an aerosol of fine particles with enhanced physical stability. The dependence of physical stability of the aerosol on the species of organism and the nature of the suspending medium for lyophilization is indicated. Also, limitations and general applicability of both the technique and results are discussed. PMID:4992657

  17. Space Borne Cloud and Aerosol Measurements by the Geoscience Laser Altimeter System: Initial Results

    NASA Technical Reports Server (NTRS)

    Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis L.; Hart, William D.; Mahesh, Ashwin; Welton, Ellsworth J.

    2003-01-01

    In January 2003 the Geoscience Laser Altimeter System (GLAS) was successfully launched into orbit. Beginning in March 2003 GLAS will provide global coverage lidar measurement of the height distribution of clouds and aerosol in the atmosphere for up to five years. The characteristic and value of the unique data will be presented. The instrument is a basic backscatter lidar that operates at two wavelengths, 532 and 1064 nm. The mission data products for atmospheric observations include the calibrated, observed, attenuated backscatter cross section for cloud and aerosol; height detection for multiple cloud layers; planetary boundary layer height; cirrus and aerosol optical depth and the height distribution of aerosol and cloud scattering cross section profiles. The data is expected to significantly enhance knowledge in several areas of atmospheric science, in particular the distribution, transport and influence of atmospheric aerosol and thin clouds. Measurements of the coverage and height of polar and cirrus cloud should be significantly more accurate than previous global observations. In March and April 2003, airborne and ground based data verification experiments will be carried out. Initial results from the verification experiments and the first several months of operation will be presented.

  18. A comparison of Teflon slides and the Army Insecticide Measuring System for sampling aerosol clouds.

    PubMed

    Brown, J R; Dukes, J C; Beidler, E J; Chew, V; Ruff, J

    1993-03-01

    The effects of method of droplet analysis, reader of Teflon slides and distance on mass median diameter of a Cythion aerosol cloud were examined in the calibration of an Army Insecticide Measuring System (AIMS). There were no significant differences in results among readers and between the AIMS and readers. There were slight but statistically significant differences between readers of Teflon slides and between the methods of analysis. Data supports the manufacturer's recommendation that, for the AIMS, the distance at which an aerosol generator air blast is between 3 and 7 m3 s-1 must be determined.

  19. [New ways in aerosol therapy. Development of FCKW-free gases-- powder inhalation systems].

    PubMed

    Haidl, G P

    1999-03-20

    New approaches in the field of aerosol therapy are pointing into two directions. In one, chlorofluorocarbons are now beginning to make place for the hydrofluoroalkanes--which are non-destructive of the ozone layer--as propellants for use in metered-dose inhalers. On the other hand, the use and new development of dry powder inhalation devices are on the increase. In the future, systemic pharmacotherapy applied via aerosols will provide an important option for use not only in the field of pneumology, but also, for example, in the treatment of diabetes mellitus and for anticoagulation.

  20. Real-time detection method and system for identifying individual aerosol particles

    DOEpatents

    Gard, Eric E.; Coffee, Keith R.; Frank, Matthias; Tobias, Herbert J.; Fergenson, David P.; Madden, Norm; Riot, Vincent J.; Steele, Paul T.; Woods, Bruce W.

    2007-08-21

    An improved method and system of identifying individual aerosol particles in real time. Sample aerosol particles are collimated, tracked, and screened to determine which ones qualify for mass spectrometric analysis based on predetermined qualification or selection criteria. Screening techniques include one or more of determining particle size, shape, symmetry, and fluorescence. Only qualifying particles passing all screening criteria are subject to desorption/ionization and single particle mass spectrometry to produce corresponding test spectra, which is used to determine the identities of each of the qualifying aerosol particles by comparing the test spectra against predetermined spectra for known particle types. In this manner, activation cycling of a particle ablation laser of a single particle mass spectrometer is reduced.

  1. Generation and delivery of coal liquid aerosols for inhalation studies

    SciTech Connect

    Springer, D.L.; Clark, M.L.; Willard, D.H.; Mahlum, D.D.

    1982-07-01

    To aid in the toxicologic evaluation of solvent refined coal (SRC) materials, we developed an aerosol generation system for whole-body inhalation exposure of experimental animals to coal liquids. The main components of the exposure system were an aerosol generator, a manifold for delivery of the aerosol, three exposure chambers and an exhaust system. High-boiling coal liquids from the SRC-l and the SRC-ll processes were as test materials. Aerosol concentrations were measured by drawing aerosol samples from the chambers through a Metricel filter and eluting the coal liquid into chloroform.Since these coal liquids have an ultraviolet absorption peak at 254 mm, the absorbance was determined at this wavelength. As part of the experiment, we evaluated the Solo-Sphere, Rec and Collison neubulizer as aerosol generators for the coal liquids. Both the Solo-Sphere and Retec provided adequate concentrations of respirable particles; however, aerosol concentrations within the exposure chamber provided adequate concentrations of respirable particles; however, aerosol concentrations within the exposure chamber were more consistent with the Solo-Sphere. Low mass output and plugging were encountered with the Collison. Use of the Solo-Sphere generator and manifold delivery system resulted in consistent and uniform aerosol concentrations and particle sizes in the exposure chamber over a 15-day test period. Analysis of the chamber atmosphere when SRC-l process solvent was used indicated the presence of vapors as well as particles. The ultraviolet absorption spectrum suggested that two-ring polynuclear aromatic compounds were the major constituents of the vapor phase.

  2. Aerosol-cloud-precipitation system as a predator-prey problem.

    PubMed

    Koren, Ilan; Feingold, Graham

    2011-07-26

    We show that the aerosol-cloud-precipitation system exhibits characteristics of the predator-prey problem in the field of population dynamics. Both a detailed large eddy simulation of the dynamics and microphysics of a precipitating shallow boundary layer cloud system and a simpler model built upon basic physical principles, reproduce predator-prey behavior with rain acting as the predator and cloud as the prey. The aerosol is shown to modulate the predator-prey response. Steady-state solution to the proposed model shows the known existence of bistability in cloudiness. Three regimes are identified in the time-dependent solutions: (i) the weakly precipitating regime where cloud and rain coexist in a quasi steady state; (ii) the moderately drizzling regime where limit-cycle behavior in the cloud and rain fields is produced; and (iii) the heavily precipitating clouds where collapse of the boundary layer is predicted. The manifestation of predator-prey behavior in the aerosol-cloud-precipitation system is a further example of the self-organizing properties of the system and suggests that exploiting principles of population dynamics may help reduce complex aerosol-cloud-rain interactions to a more tractable problem.

  3. NEW VERSATILE AEROSOL GENERATION SYSTEM DEVELOPED FOR USE IN A LARGE WIND TUNNEL

    EPA Science Inventory

    A new aerosol generation system was developed to accommodate a variety of research activities performed within a large wind tunnel. Because many of the velocity measurements are taken in the wind tunnel with a laser Doppler anemometer (LDA), it is necessary to maintain an aero...

  4. Aerosolized Antibiotics.

    PubMed

    Restrepo, Marcos I; Keyt, Holly; Reyes, Luis F

    2015-06-01

    Administration of medications via aerosolization is potentially an ideal strategy to treat airway diseases. This delivery method ensures high concentrations of the medication in the targeted tissues, the airways, with generally lower systemic absorption and systemic adverse effects. Aerosolized antibiotics have been tested as treatment for bacterial infections in patients with cystic fibrosis (CF), non-CF bronchiectasis (NCFB), and ventilator-associated pneumonia (VAP). The most successful application of this to date is treatment of infections in patients with CF. It has been hypothesized that similar success would be seen in NCFB and in difficult-to-treat hospital-acquired infections such as VAP. This review summarizes the available evidence supporting the use of aerosolized antibiotics and addresses the specific considerations that clinicians should recognize when prescribing an aerosolized antibiotic for patients with CF, NCFB, and VAP.

  5. The response of a simulated Mesoscale Convective System to increased aerosol pollution

    NASA Astrophysics Data System (ADS)

    Clavner, Michal

    This work focuses on the impacts of aerosols on the total precipitation amount, rates and spatial distribution of precipitation produced by a Mesoscale Convective System (MCS), as well as the characteristics of a derecho event. Past studies have shown that the impacts on MCS-produced precipitation to changes in aerosol concentration are strongly dependent on environmental conditions, primarily humidity and environmental wind shear. Changes in aerosol concentrations were found to alter MCS-precipitation production directly by modifying precipitation processes and indirectly by affecting the efficiency of the storm's self-propagation. Observational and numerical studies have been conducted that have examined the dynamics responsible for the generation of widespread convectively-induced windstorms, primarily focusing on environmental conditions and the MCS features that generate a derecho event. While the sensitivity of the formation of bow-echoes, the radar signature associated with derecho events, to changes in microphysics has been examined, a study on a derecho-producing MCS characteristics to aerosol concentrations has not. In this study different aerosol concentrations and their effects on precipitation and a derecho produced by an MCS are examined by simulating the 8 May 2009 "Super-Derecho" MCS. The MCS was simulated using the Regional Atmospheric Modeling System (RAMS), a cloud-resolving model (CRM) with sophisticated aerosol and microphysical parameterizations. Three simulations were conducted that varied in their initial aerosol concentration, distribution and hygroscopicity as determined by their emission sources. The first simulation contained aerosols from only natural sources and the second with aerosols sourced from both natural and anthropogenic emissions The third simulation contained the same aerosol distribution as in the second simulation, however multiplied by a factor of 5 in order to represent a highly polluted scenario. In all three of the

  6. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems.

    PubMed

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs' lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs' lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs' lifetime. AOD explains up to 24% of the total variance of MCSs' lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs' ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs' lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs' lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs' lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions. PMID:27313203

  7. Relative influence of meteorological conditions and aerosols on the lifetime of mesoscale convective systems

    NASA Astrophysics Data System (ADS)

    Chakraborty, Sudip; Fu, Rong; Massie, Steven T.; Stephens, Graeme

    2016-07-01

    Using collocated measurements from geostationary and polar-orbital satellites over tropical continents, we provide a large-scale statistical assessment of the relative influence of aerosols and meteorological conditions on the lifetime of mesoscale convective systems (MCSs). Our results show that MCSs’ lifetime increases by 3-24 h when vertical wind shear (VWS) and convective available potential energy (CAPE) are moderate to high and ambient aerosol optical depth (AOD) increases by 1 SD (1σ). However, this influence is not as strong as that of CAPE, relative humidity, and VWS, which increase MCSs’ lifetime by 3-30 h, 3-27 h, and 3-30 h per 1σ of these variables and explain up to 36%, 45%, and 34%, respectively, of the variance of the MCSs’ lifetime. AOD explains up to 24% of the total variance of MCSs’ lifetime during the decay phase. This result is physically consistent with that of the variation of the MCSs’ ice water content (IWC) with aerosols, which accounts for 35% and 27% of the total variance of the IWC in convective cores and anvil, respectively, during the decay phase. The effect of aerosols on MCSs’ lifetime varies between different continents. AOD appears to explain up to 20-22% of the total variance of MCSs’ lifetime over equatorial South America compared with 8% over equatorial Africa. Aerosols over the Indian Ocean can explain 20% of total variance of MCSs’ lifetime over South Asia because such MCSs form and develop over the ocean. These regional differences of aerosol impacts may be linked to different meteorological conditions.

  8. Variation of radon-222 concentration in exposure systems air under different conditions of exposure

    NASA Astrophysics Data System (ADS)

    Mamoon, A.; Abdul-Fattah, A. A.; Qari, T. M.

    1994-07-01

    Simplified, laboratory scale systems, namely ordinary laboratory desiccators and cylindrical containers were tested with regard to their reliability as exposure systems for determining certain parameters of radon emanation from locally obtained crushed granite rock samples. The samples were placed inside the exposure systems. Activity concentration of emanated radon in the exposure systems air increased with increase of mass of granite sample in the desiccator and with length of the exposure period. Activity concentration of radon was high near the granitic source but decreased with vertical distance from it when the exposure system was semiclosed but activity was homogeneous when the system was completely closed. The cylindrical exposure system was used in assessing Ra-226 content in some crushed granitic samples identified as altered alkali granite and found to be: 0.024 Bq g-1 (0.65 pCig-1). Rn-222 emanation rate from the same samples was: 0.013 Bq m-2 s-1 (0.34 pCi m-2 s-1). Saturation density thickness for a mixed sample of pure and alkali granites was found to be 116 g cm-2. The results agree in general with reported observations and support the reliability of the exposure systems used.

  9. Increasing the Time of Exposure to Aerosol Measles Vaccine Elicits an Immune Response Equivalent to That Seen in 9-Month-Old Mexican Children Given the Same Dose Subcutaneously

    PubMed Central

    García-León, Miguel Leonardo; Espinosa-Torres Torrija, Bogart; Hernández-Pérez, Brenda; Cardiel-Marmolejo, Lino E.; Beeler, Judy A.; Audet, Susette; Santos-Preciado, José Ignacio

    2011-01-01

    Background. A 30-second aerosol measles vaccination successfully primes children 12 months of age and older but is poorly immunogenic when given to 9-month-old children. We examined the immune responses when increasing the duration to aerosol exposure in 9-month-olds. Methods. One hundred and thirteen healthy 9-month-old children from Mexico City were enrolled; 58 received aerosol EZ measles vaccine for 2.5 minutes and 55 subcutaneously. Measles-specific neutralizing antibodies and cellular responses were measured before and at 3 and 6 months postimmunization. Results. Adaptive immunity was induced in 97% after aerosol and 98% after subcutaneous administration. Seroconversion rates and GMCs were 95% and 373 mIU/mL (95% confidence interval [CI], 441–843) following aerosol vaccination and 91% and 306 mIU/mL (95% CI, 367–597) after subcutaneous administration at 3 months. The percentage of children with a measles-specific stimulation index ≥3 was 45% and 60% in the aerosol versus 55% and 59% in the subcutaneous group at 3 and 6 months, respectively. CD8 memory cell frequencies were higher in the aerosol group at 3 months compared with the subcutaneous group. Adverse reactions were comparable in both groups. Conclusions. Increasing exposure time to aerosol measles vaccine elicits immune responses that are comparable to those seen when an equivalent dose is administered by the subcutaneous route in 9-month-old infants. PMID:21742842

  10. Effect of high concentrations of inorganic seed aerosols on secondary organic aerosol formation in the m-xylene/NO x photooxidation system

    NASA Astrophysics Data System (ADS)

    Lu, Zifeng; Hao, Jiming; Takekawa, Hideto; Hu, Lanhua; Li, Junhua

    High concentrations (>15 μm 3 cm -3) of CaSO 4, Ca(NO 3) 2 and (NH 4) 2SO 4 were selected as surrogates of dry neutral, aqueous neutral and dry acidic inorganic seed aerosols, respectively, to study the effects of inorganic seeds on secondary organic aerosol (SOA) formation in irradiated m-xylene/NO x photooxidation systems. The results indicate that neither ozone formation nor SOA formation is significantly affected by the presence of neutral aerosols (both dry CaSO 4 and aqueous Ca(NO 3) 2), even at elevated concentrations. The presence of high concentrations of (NH 4) 2SO 4 aerosols (dry acidic) has no obvious effect on ozone formation, but it does enhance SOA generation and increase SOA yields. In addition, the effect of dry (NH 4) 2SO 4 on SOA yield is found to be positively correlated with the (NH 4) 2SO 4 surface concentration, and the effect is pronounced only when the surface concentration reaches a threshold value. Further, it is proposed that the SOA generation enhancement is achieved by particle-phase heterogeneous reactions induced and catalyzed by the acidity of dry (NH 4) 2SO 4 seed aerosols.

  11. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.

    2015-12-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under CMA chemical weather modeling system GRAPES/CUACE. Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) is fed online interactively into a two-moment cloud scheme (WDM6) and a convective parameterization to drive the cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred. The results show that interactive aerosols with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content and cloud droplet number concentrations while decrease the mean diameter of cloud droplets with varying magnitudes of the changes in each case and region. These interactive micro-physical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24% to 48% enhancements of TS scoring for 6-h precipitation in almost all regions. The interactive aerosols with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3°C.

  12. Comparison of secondary organic aerosol formed with an aerosol flow reactor and environmental reaction chambers: effect of oxidant concentration, exposure time and seed particles on chemical composition and yield

    DOE PAGES

    Lambe, A. T.; Chhabra, P. S.; Onasch, T. B.; Brune, W. H.; Hunter, J. F.; Kroll, J. H.; Cummings, M. J.; Brogan, J. F.; Parmar, Y.; Worsnop, D. R.; et al

    2014-12-02

    We performed a systematic intercomparison study of the chemistry and yields of SOA generated from OH oxidation of a common set of gas-phase precursors in a Potential Aerosol Mass (PAM) continuous flow reactor and several environmental chambers. In the flow reactor, SOA precursors were oxidized using OH concentrations ranging from 2.0×108 to 2.2×1010 molec cm-3 over exposure times of 100 s. In the environmental chambers, precursors were oxidized using OH concentrations ranging from 2×106 to 2×107 molec cm-3 over exposure times of several hours. The OH concentration in the chamber experiments is close to that found in the atmosphere, butmore » the integrated OH exposure in the flow reactor can simulate atmospheric exposure times of multiple days compared to chamber exposure times of only a day or so. A linear correlation analysis of the mass spectra (m=0.91–0.92, r2=0.93–0.94) and carbon oxidation state (m=1.1, r2=0.58) of SOA produced in the flow reactor and environmental chambers for OH exposures of approximately 1011 molec cm-3 s suggests that the composition of SOA produced in the flow reactor and chambers is the same within experimental accuracy as measured with an aerosol mass spectrometer. This similarity in turn suggests that both in the flow reactor and in chambers, SOA chemical composition at low OH exposure is governed primarily by gas-phase OH oxidation of the precursors, rather than heterogeneous oxidation of the condensed particles. In general, SOA yields measured in the flow reactor are lower than measured in chambers for the range of equivalent OH exposures that can be measured in both the flow reactor and chambers. The influence of sulfate seed particles on isoprene SOA yield measurements was examined in the flow reactor. The studies show that seed particles increase the yield of SOA produced in flow reactors by a factor of 3 to 5 and may also account in part for higher SOA yields obtained in the chambers, where seed particles are

  13. Pulmonary aerosol actions of LY188695 (KB2413), a new potent H1-receptor antagonist.

    PubMed

    Silbaugh, S A; Stengel, P W; Rinkema, L E

    1987-06-01

    The new potent H1 receptor antagonist, LY188695 (KB2413), was delivered to guinea pigs as a pulmonary aerosol and its ability to inhibit histamine-induced airway obstruction examined. Aerosol LY188695 was more effective than inhaled chlorpheniramine or clemastine in reducing the pulmonary gas trapping produced by histamine challenge. Lung antihistamine effects occurred within minutes of a brief, low concentration aerosol exposure and persisted for at least 1 hour. LY188695 aerosol treatment did not produce significant inhibition of methacholine-induced gas trapping. Although systemic antihistamine effects occurred 50 minutes after LY188695 inhalation, aerosol administration produced an enhanced local (i.e., lung) action compared to intravenous delivery.

  14. Aerosol seeding systems for the NSWC wind tunnels

    NASA Technical Reports Server (NTRS)

    Yanta, W. J.; Smith, T. S.; Collier, A. S.

    1985-01-01

    Four types of laskin nozzles which are used to generate the primary aerosol mist are illustrated. This mist may be used directly as laser doppler velocimeters (LDV) particles. However, in general, a wide range of particle size exists at this stage and requires the use of some type of mono-dispersion refinement technique. These nozzles rely on the shearing action of high speed air near a column of seeding liquid. Typically, olive oil or dioctyl phthalate (DOP) is used, but within the past year solid polystyrene particles in an alcohol suspension have been used with great success. Air, at a typical pressure of five psig, is supplied to the top of the nozzle which is merely a hollow tube. This air issues radially from one or more small jets located near the collar close to the bottom of the tube. When the collar is submerged in the seeding liquid, the hollow columns located in the collar become filled with liquid. The air from the jet shears the liquid into the fine mist.

  15. Engineering Upgrades to the Radionuclide Aerosol Sampler/Analyzer for the CTBT International Monitoring System

    SciTech Connect

    Forrester, Joel B.; Carty, Fitz; Comes, Laura; Hayes, James C.; Miley, Harry S.; Morris, Scott J.; Ripplinger, Mike D.; Slaugh, Ryan W.; Van Davelaar, Peter

    2013-05-13

    The Radionuclide Aerosol Sampler/Analyzer (RASA) is an automated aerosol collection and analysis system designed by Pacific Northwest National Laboratory in the 1990’s and is deployed in several locations around the world as part of the International Monitoring System (IMS) required under the Comprehensive Nuclear-Test-Ban Treaty (CTBT). The utility of such an automated system is the reduction of human intervention and the production of perfectly uniform results. However, maintainability and down time issues threaten this utility, even for systems with over 90% data availability. Engineering upgrades to the RASA are currently being pursued to address these issues, as well as Fukushima lessons learned. Current work includes a new automation control unit, and other potential improvements such as alternative detector cooling and sampling options are under review. This paper presents the current state of upgrades and improvements under investigation

  16. Raman lidar system for the measurement of water vapor and aerosols in the earth's atmosphere

    NASA Technical Reports Server (NTRS)

    Whiteman, D. N.; Melfi, S. H.; Ferrare, R. A.

    1992-01-01

    A nighttime operating Raman lidar system that is designed for the measurement of high vertical and temporal resolution profiles of the water vapor mixing ratio and the aerosol backscattering ratio is described. The theory of the measurements is presented. Particular attention is given to operational problems that have been solved during the development of the system. Data are presented from Sept. 1987 and described in their meteorological context.

  17. The System of the Calibration for Visibility Measurement Instrument Under the Atmospheric Aerosol Simulation Environment

    NASA Astrophysics Data System (ADS)

    Shu, Zhifeng; Yang, ShaoChen; Xu, Wenjing

    2016-06-01

    Visibility is one of the most important parameters for meteorological observation and numerical weather prediction (NWP).It is also an important factor in everyday life, mainly for surface and air traffic especially in the Aeronautical Meteorology. The visibility decides the taking off and landing of aircraft. If the airport visibility is lower than requirement for aircraft taking off stipulated by International Civil Aviation Administration, then the aircraft must be parked at the airport. So the accurate measurement of visibility is very important. Nowadays, many devices can be measured the visibility or meteorological optical range (MOR) such as Scatterometers, Transmissometers and visibility lidar. But there is not effective way to verify the accuracy of these devices expect the artificial visual method. We have developed a visibility testing system that can be calibration and verification these devices. The system consists of laser transmitter, optical chopper, phase-locking amplifier, the moving optic receiving system, signal detection and data acquisition system, atmospheric aerosol simulation chamber. All of them were placed in the atmosphere aerosol simulation chamber with uniform aerosol concentration. The Continuous wave laser, wavelength 550nm, has been transmitted into the collimation system then the laser beam expanded into 40mm diameter for compressing the laser divergence angle before modulated by optical chopper. The expanding beam transmitting in the atmosphere aerosol cabin received by the optic receiving system moving in the 50m length precision guide with 100mm optical aperture. The data of laser signal has been acquired by phase-locking amplifier every 5 meter range. So the 10 data points can be detected in the 50 meters guide once. The slope of the fitting curve can be obtained by linear fitting these data using the least square method. The laser extinction coefficient was calculated from the slope using the Koschmieder formula, then it been

  18. Pathology of experimental Machupo virus infection, Chicava strain, in cynomolgus macaques (Macaca fascicularis) by intramuscular and aerosol exposure.

    PubMed

    Bell, T M; Shaia, C I; Bunton, T E; Robinson, C G; Wilkinson, E R; Hensley, L E; Cashman, K A

    2015-01-01

    Machupo virus, the causative agent of Bolivian hemorrhagic fever (BHF), is a highly lethal viral hemorrhagic fever of which little is known and for which no Food and Drug Administration-approved vaccines or therapeutics are available. This study evaluated the cynomolgus macaque as an animal model using the Machupo virus, Chicava strain, via intramuscular and aerosol challenge. The incubation period was 6 to 10 days with initial signs of depression, anorexia, diarrhea, mild fever, and a petechial skin rash. These were often followed by neurologic signs and death within an average of 18 days. Complete blood counts revealed leukopenia as well as marked thrombocytopenia. Serum chemistry values identified a decrease in total protein, marked increases in alanine aminotransferase and aspartate aminotransferase, and moderate increases in alkaline phosphatase. Gross pathology findings included a macular rash extending across the axillary and inguinal regions beginning at approximately 10 days postexposure as well as enlarged lymph nodes and spleen, enlarged and friable liver, and sporadic hemorrhages along the gastrointestinal mucosa and serosa. Histologic lesions consisted of foci of degeneration and necrosis/apoptosis in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, stomach, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system (nonsuppurative encephalitis) was histologically apparent approximately 16 days postexposure and was generally progressive. This study provides insight into the course of Machupo virus infection in cynomolgus macaques and supports the usefulness of cynomolgus macaques as a viable model of human Machupo virus infection.

  19. Whole-body aerosol exposure of cadmium chloride (CdCl2) and tetrabromobisphenol A (TBBPA) induced hepatic changes in CD-1 male mice.

    PubMed

    Chen, Yuanhong; Hu, Yabing; Liu, Shuyun; Zheng, Huiying; Wu, Xiaojuan; Huang, Zhengyu; Li, Hao; Peng, Baoqi; Long, Jinlie; Pan, Bishu; Huang, Changjiang; Dong, Qiaoxiang

    2016-11-15

    Cadmium (Cd) and tetrabromobisphenol A (TBBPA) are two prevalent contaminants in e-waste recycling facilities. However, the potential adversely health effect of co-exposure to these two types of pollutants in an occupational setting is unknown. In this study, we investigated co-exposure of these two pollutants on hepatic toxicity in CD-1 male mice through a whole-body aerosol inhalation route. Specifically, mice were exposed to solvent control (5% DMSO), Cd (8μg/m(3)), TBBPA (16μg/m(3)) and Cd/TBBPA mixture for 8h/day and 6days a week for 60 days. Hepatic changes include increased organ weight, focal necrosis, and elevated levels of liver enzymes in serum. These changes were most severe in mice exposed to TBBPA, followed by Cd/TBBPA mixture and Cd. These chemicals also led to suppressed antioxidant defensive mechanisms and increased oxidative stress. Further, these chemicals induced gene expression of apoptosis-related genes, activated genes encoding for phase I detoxification enzymes and inhibited genes encoding for phase II detoxification enzymes. These findings indicate that the hepatic damages induced by subchronic aerosol exposure of Cd and TBBPA may result from the oxidative damages caused by excessive ROS production when these chemicals were metabolized in the liver.

  20. Whole-body aerosol exposure of cadmium chloride (CdCl2) and tetrabromobisphenol A (TBBPA) induced hepatic changes in CD-1 male mice.

    PubMed

    Chen, Yuanhong; Hu, Yabing; Liu, Shuyun; Zheng, Huiying; Wu, Xiaojuan; Huang, Zhengyu; Li, Hao; Peng, Baoqi; Long, Jinlie; Pan, Bishu; Huang, Changjiang; Dong, Qiaoxiang

    2016-11-15

    Cadmium (Cd) and tetrabromobisphenol A (TBBPA) are two prevalent contaminants in e-waste recycling facilities. However, the potential adversely health effect of co-exposure to these two types of pollutants in an occupational setting is unknown. In this study, we investigated co-exposure of these two pollutants on hepatic toxicity in CD-1 male mice through a whole-body aerosol inhalation route. Specifically, mice were exposed to solvent control (5% DMSO), Cd (8μg/m(3)), TBBPA (16μg/m(3)) and Cd/TBBPA mixture for 8h/day and 6days a week for 60 days. Hepatic changes include increased organ weight, focal necrosis, and elevated levels of liver enzymes in serum. These changes were most severe in mice exposed to TBBPA, followed by Cd/TBBPA mixture and Cd. These chemicals also led to suppressed antioxidant defensive mechanisms and increased oxidative stress. Further, these chemicals induced gene expression of apoptosis-related genes, activated genes encoding for phase I detoxification enzymes and inhibited genes encoding for phase II detoxification enzymes. These findings indicate that the hepatic damages induced by subchronic aerosol exposure of Cd and TBBPA may result from the oxidative damages caused by excessive ROS production when these chemicals were metabolized in the liver. PMID:27415598

  1. Effect of Aerosol Variation on Radiance in the Earth's Atmosphere-Ocean System.

    PubMed

    Plass, G N; Kattawar, G W

    1972-07-01

    The reflected and transmitted radiance is calculated for a realistic model of the atmosphere-ocean system. Multiple scattering to all orders as well as anisotropic scattering from aerosols are taken into account by a Monte Carlo technique. The probability for reflection or refraction at the ocean surface is calculated for each photon. Scattering and absorption by water molecules (Rayleigh) and by hydrosols (Mie) are taken into account within the ocean. The radiance is calculated for a normal aerosol distribution as well as for a three and ten times normal distribution. Calculations are also made for an aerosol layer near the earth as well as for one in the stratosphere. The upward radiance at the top of the atmosphere depends strongly on the total number of aerosols but not on their spatial distribution. Variations in the ozone amount also have little effect on the upward radiance. The calculations are made at the following wavelengths: 0.7 micro, 0.9 micro, 1.67 micro. The radiance above and below the ocean surface as well as the flux at various levels are also discussed.

  2. Phases and Phase Changes of Mixed Organic/Inorganic Model Systems of Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Marcolli, C.; Krieger, U. K.; Zardini, A. A.; Zobrist, B.; Zuend, A.; Luo, B. P.; Peter, T.

    2006-12-01

    Knowledge of the physical state of tropospheric aerosols is important for an adequate description of cloud formation, heterogeneous and multiphase chemistry, and the aerosol's radiative properties. We will present and discuss laboratory experiments on bulk aerosol model mixtures and micron-sized particles consisting of polyols, polyethylene glycol or dicarboxylic acids mixed with ammonium sulfate. Depending on the exact composition and relative humidity, these mixtures form liquid-one-phase or two-phase systems plus additional solid phases. Whilst the organic matter in ambient aerosols is expected to be predominantly present in the form of liquid or amorphous phases, the inorganic salts may still undergo deliquescence and efflorescence as a function of relative humidity. Moreover, they may induce phase separations into a predominantly organic and an inorganic aqueous phase. In the absence of solid phases, the water uptake and release of the investigated micron-sized particles was usually well described by the Zdanovskii-Stokes-Robinson (ZSR) approach. However, this model became inaccurate when solid phases were present. Moreover, it is not able to account for liquid-liquid phase separations due to the salting-out effects of the investigated inorganic salts. While most organics participate in liquid phases some organic substances are abundant enough in the particles to form crystalline solids that might act as ice nuclei. We show that this is the case for oxalic acid.

  3. New Lidar Capabilities in Space: An Overview of the Cloud-Aerosol Transport System (CATS)

    NASA Astrophysics Data System (ADS)

    McGill, M. J.; Yorks, J. E.; Hlavka, D. L.; Selmer, P. A.; Hart, W. D.; Palm, S. P.; Nowottnick, E. P.; Vaughan, M.; Rodier, S. D.; Colarco, P. R.; da Silva, A.; Buchard, V.

    2014-12-01

    The Cloud-Aerosol Transport System (CATS), built at NASA Goddard Space Flight Center as a payload for the International Space Station (ISS), is set to launch in the late 2014. CATS is an elastic backscatter lidar operating in one of three science modes with three wavelengths (1064, 532, 355 nm) and HSRL capability at 532 nm. Depolarization measurements will be made at the 532 and 1064 nm wavelengths. The CATS science modes are described in Figure 1. The ISS orbit is a 51 degree inclination orbit at an altitude of about 405 km. This orbit provides more comprehensive coverage of the tropics and mid-latitudes than sun-synchronous orbiting sensors, with nearly a three day repeat cycle. Thus, science applications of CATS include cloud and aerosol climate studies, air quality monitoring, and smoke/volcanic plume tracking. Current uncertainties in cloud and aerosol properties limit our ability to accurately model the Earth's climate system and predict climate change. These limitations are due primarily to difficulties in adequately measuring aerosols and clouds on a global scale. A primary science objectives of CATS is to provide global aerosol and cloud vertical profile data in near real time to for assimilation in aerosol transport models such as the NASA GEOS-5 model. Furthermore, the vertical profiles of cloud and aerosol properties provided by CATS will complement current and future passive satellite sensors. Another important science objective of CATS is to advance technology in support of future mission development. CATS will employ 355 nm and HSRL capabilities, as well as depolarization at multiple wavelengths. These expanded measurement capabilities will provide the science community with new and improved global data products that have yet to be retrieved from space-based lidar. In preparation for launch, simulations of the CATS lidar signal are produced using GEOS5 model data to develop and test future data products. An example of the simulated CATS attenuated

  4. Topical nitrogen mustard exposure causes systemic toxic effects in mice

    PubMed Central

    Goswami, Dinesh G.; Kumar, Dileep; Tewari-Singh, Neera; Orlicky, David J.; Jain, Anil K.; Kant, Rama; Rancourt, Raymond C.; Dhar, Deepanshi; Inturi, Swetha; Agarwal, Chapla; White, Carl W.; Agarwal, Rajesh

    2014-01-01

    Vesicating agents sulfur mustard (SM) and nitrogen mustard (NM) are reported to be easily absorbed by skin upon exposure causing severe cutaneous injury and blistering. Our studies show that topical exposure of NM (3.2 mg) onto SKH-1 hairless mouse skin, not only caused skin injury, but also led to significant body weight loss and 40–80 % mortality (120 h post-exposure), suggesting its systemic effects. Accordingly, further studies herein show that NM exposure initiated an increase in circulating white blood cells by 24 h (neutrophils, eosinophils and basophils) and thereafter a decrease (neutrophils, lymphocytes and monocytes). NM exposure also reduced both white and red pulp areas of the spleen. In the small intestine, NM exposure caused loss of membrane integrity of the surface epithelium, abnormal structure of glands and degeneration of villi. NM exposure also resulted in the dilation of glomerular capillaries of kidneys, and an increase in blood urea nitrogen/creatinine ratio. Our results here with NM are consistent with earlier reports that exposure to higher SM levels can cause damage to the hematopoietic system, and kidney, spleen and gastrointestinal tract toxicity. These outcomes will add to our understanding of the toxic effects of topical vesicant exposure, which might be helpful towards developing effective countermeasures against injuries from acute topical exposures. PMID:25481215

  5. Global Aerosol Observations

    Atmospheric Science Data Center

    2013-04-19

    ... atmosphere, directly influencing global climate and human health. Ground-based networks that accurately measure column aerosol amount and ... being used to improve Air Quality Models and for regional health studies. To assess the human-health impact of chronic aerosol exposure, ...

  6. Effects of explosively venting aerosol-sized particles through earth-containment systems on the cloud-stabilization height

    SciTech Connect

    Dyckes, G.W.

    1980-07-01

    A method of approximating the cloud stabilization height for aerosol-sized particles vented explosively through earth containment systems is presented. The calculated values for stabilization heights are in fair agreement with those obtained experimentally.

  7. DEVELOPMENT AND APPLICATION OF A NEW AIR POLLUTION MODELING SYSTEM--II. AEROSOL MODULE STRUCTURE AND DESIGN (R823186)

    EPA Science Inventory

    The methods used for simulating aerosol physical and chemical processes in a new air pollution modeling system are discussed and analyzed. Such processes include emissions, nucleation, coagulation, reversible chemistry, condensation, dissolution, evaporation, irreversible chem...

  8. Construction, Modeling and Testing of a Low-Flow, Large-Diameter Aerosol Flow System for the Study of the Formation and Reactions of Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Ezell, M. J.; Johnson, S. N.; Yu, Y.; Pokkunuri, P.; Perraud, V.; Bruns, E.; Alexander, M.; Zelenyuk, A.; Dabdub, D.; Finlayson-Pitts, B. J.

    2008-12-01

    A unique, high-volume, low-flow, stainless steel aerosol flow system for the study of the formation and reactions of aerosols relevant to the troposphere has been constructed, modeled and experimentally tested. The total flow tube length is 7.3 m which includes a 1.2 m section used for mixing. The flow tube is equipped with ultraviolet lamps for photolysis. The diameter of 0.45 m results in a smaller surface to volume ratio than is found in many other flow systems and reduces the contribution of wall reactions. The latter is also reduced by frequent cleaning of the flow tube walls which is feasible due to the ease of disassembly of the flow tube. Flow systems present a major advantage over chamber studies in that continuous sampling under stable conditions over long periods of time is possible, increasing the amount of sample available for analysis and permitting a wide variety of analytical techniques to be applied simultaneously. In this system, the large volume (1000 L) and low flow speed (2 cm/minute) result in a residence time of nearly an hour; and equally spaced sampling ports allow for time-resolved measurements of aerosol and gas-phase products. The central features of this system have been modeled using computational fluid dynamics software and experimentally probed using inert gases and aerosols. Instrumentation attached directly to this flow system includes a NOx analyzer, an ozone analyzer, relative humidity and temperature probes, a scanning mobility particle sizer (SMPS) spectrometer, an aerodynamic particle sizer (APS) spectrometer, GC-MS, integrating nephelometer, and FTIR. Particles are collected using impactors and filters, and analyzed by a variety of techniques including FTIR, electrospray ionization mass spectrometry (ESI-MS), atmospheric pressure chemical ionization mass spectrometry (APCI-MS), GC-MS, HPLC-UV and HPLC-MS. In addition, for selected studies, an aerosol mass spectrometer (AMS), a single particle mass spectrometer (SPLAT II) and

  9. Determination of the passing efficiency for aerosol chemical species through a typical aircraft-mounted, diffuser-type aerosol inlet system

    NASA Astrophysics Data System (ADS)

    Sheridan, Patrick J.; Norton, Richard B.

    1998-04-01

    To assess the particle transmission efficiency of a conventional aircraft-mounted, diffuser-type inlet (CI), a new design inlet containing an internal filter basket assembly (aerosol filter inlet, or AFI) was constructed. All interior surfaces of the AFI were covered with filter material, and air was actively pulled through these filter walls during aerosol sampling. The AFI was demonstrated in the laboratory to trap nearly all particles entering its nozzle orifice, so it was considered usable as a baseline to judge the performance of other inlets. Wind tunnel studies were conducted at three different wind velocities that approximated typical research aircraft speeds. As wind velocity increased, particle transmission through the CI relative to the AFI decreased, as evidenced by chemical analysis of the filter deposits. Aircraft studies of the two inlets showed that particle transmission varied significantly with the measured species. Typical coarse-particle species such as Ca++, Mg++, Na+ and K+ showed 50-90% mass losses through a conventional diffuser-type inlet/curved intake tube system. Predominantly fine particle species such as SO4= and NH4+ passed the CI system with much higher efficiencies, with aerosol mass losses of 0-26% for most flights. Since the AFI traps nearly all particles aspirated into its nozzle orifice, these values indicate that on average, 80-90% of the SO4= and NH4+ aerosol mass passes through the CI and curved intake tube during airborne sampling. This finding suggests that the capability to sample fine (i.e., submicrometer) aerosols from aircraft is perhaps not as bad as has been previously reported, given that adequate attention is paid to inlet design, location, and orientation issues.

  10. Pathology of experimental Machupo virus infection, Chicava strain, in cynomolgus macaques (Macaca fascicularis) by intramuscular and aerosol exposure.

    PubMed

    Bell, T M; Shaia, C I; Bunton, T E; Robinson, C G; Wilkinson, E R; Hensley, L E; Cashman, K A

    2015-01-01

    Machupo virus, the causative agent of Bolivian hemorrhagic fever (BHF), is a highly lethal viral hemorrhagic fever of which little is known and for which no Food and Drug Administration-approved vaccines or therapeutics are available. This study evaluated the cynomolgus macaque as an animal model using the Machupo virus, Chicava strain, via intramuscular and aerosol challenge. The incubation period was 6 to 10 days with initial signs of depression, anorexia, diarrhea, mild fever, and a petechial skin rash. These were often followed by neurologic signs and death within an average of 18 days. Complete blood counts revealed leukopenia as well as marked thrombocytopenia. Serum chemistry values identified a decrease in total protein, marked increases in alanine aminotransferase and aspartate aminotransferase, and moderate increases in alkaline phosphatase. Gross pathology findings included a macular rash extending across the axillary and inguinal regions beginning at approximately 10 days postexposure as well as enlarged lymph nodes and spleen, enlarged and friable liver, and sporadic hemorrhages along the gastrointestinal mucosa and serosa. Histologic lesions consisted of foci of degeneration and necrosis/apoptosis in the haired skin, liver, pancreas, adrenal glands, lymph nodes, tongue, esophagus, salivary glands, stomach, small intestine, and large intestine. Lymphohistiocytic interstitial pneumonia was also present. Inflammation within the central nervous system (nonsuppurative encephalitis) was histologically apparent approximately 16 days postexposure and was generally progressive. This study provides insight into the course of Machupo virus infection in cynomolgus macaques and supports the usefulness of cynomolgus macaques as a viable model of human Machupo virus infection. PMID:24990481

  11. Aerosol distribution apparatus

    DOEpatents

    Hanson, W.D.

    An apparatus for uniformly distributing an aerosol to a plurality of filters mounted in a plenum, wherein the aerosol and air are forced through a manifold system by means of a jet pump and released into the plenum through orifices in the manifold. The apparatus allows for the simultaneous aerosol-testing of all the filters in the plenum.

  12. Influence of source distribution and geochemical composition of aerosols on children exposure in the large polymetallic mining region of the Bolivian Altiplano.

    PubMed

    Goix, Sylvaine; Point, David; Oliva, Priscia; Polve, Mireille; Duprey, Jean Louis; Mazurek, Hubert; Guislain, Ludivine; Huayta, Carlos; Barbieri, Flavia L; Gardon, Jacques

    2011-12-15

    The Bolivian Altiplano (Highlands) region is subject to intense mining, tailing and smelting activities since centuries because of the presence of large and unique polymetallic ore deposits (Ag, Au, Cu, Pb, Sn, Sb, Zn). A large scale PM(10), PM(2.5) aerosol monitoring survey was conducted during the dry season in one of the largest mining cities of this region (Oruro, 200,000 inhabitants). Aerosol fractions, source distribution and transport were investigated for 23 elements at approximately 1 km(2) scale resolution, and compared to children exposure data obtained within the same geographical space. As, Cd, Pb, Sb, W and Zn in aerosols are present at relatively high concentrations when compared to studies from other mining regions. Arsenic exceeds the European council PM(10) guide value (6 ng/m(3)) for 90% of the samples, topping 200 ng/m(3). Ag, As, Cd, Cu, Pb and Sb are present at significantly higher levels in the district located in the vicinity of the smelter zone. At the city level, principal component analysis combined with the mapping of factor scores allowed the identification and deconvolution of four individual sources: i) a natural magmatic source (Co, Cs, Fe, K, Mn, Na, Rb and U) originating from soil dust, resuspended by the traffic activity; ii) a natural sedimentary source (Mg, Ca, Sr, Ba and Th) resulting from the suspension of evaporative salt deposits located South; iii) an anthropogenic source specifically enriched in mined elements (As, Cd, Cu, Pb, Sb and Zn) mainly in the smelting district of the city; and iv) a Ni-Cr source homogenously distributed between the different city districts. Enrichment factors for As, Cd and Sb clearly show the impact of smelting activities, particularly in the finest PM(2.5) fraction. Comparison to children's hair metal contents collected in five schools from different districts shows a direct exposure to smelting activity fingerprinted by a unique trace elements pattern (Ag, As, Cu, Pb, Sb).

  13. Development of the aerosol generation system for simulating the dry deposition behavior of radioaerosol emitted by the accident of FDNPP

    NASA Astrophysics Data System (ADS)

    Zhang, Z.

    2015-12-01

    A large amount of radioactivity was discharged by the accident of FDNPP. The long half-life radionuclide, 137Cs was transported through the atmosphere mainly as the aerosol form and deposited to the forests in Fukushima prefecture. After the dry deposition of the 137Cs, the foliar uptake process would occur. To evaluate environmental transfer of radionuclides, the dry deposition and following foliar uptake is very important. There are some pioneering studies for radionuclide foliar uptake with attaching the solution containing stable target element on the leaf, however, cesium oxide aerosols were used for these deposition study [1]. In the FDNPP case, 137Cs was transported in sulfate aerosol form [2], so the oxide aerosol behaviors could not represent the actual deposition behavior in this accident. For evaluation of whole behavior of 137Cs in vegetation system, fundamental data for deposition and uptake process of sulfate aerosol was desired. In this study, we developed aerosol generation system for simulating the dry deposition and the foliar uptake behaviors of aerosol in the different chemical constitutions. In this system, the method of aerosol generation based on the spray drying. Solution contained 137Cs was send to a nozzle by a syringe pump and spraying with a high speed air flow. The sprayed mist was generated in a chamber in the relatively high temperature. The solution in the mist was dried quickly, and micro size solid aerosols consisting 137Cs were generated. The aerosols were suctioned by an ejector and transported inside a tube by the dry air flow, then were directly blown onto the leaves. The experimental condition, such as the size of chamber, chamber temperature, solution flow rate, air flow rate and so on, were optimized. In the deposition experiment, the aerosols on leaves were observed by a SEM/EDX system and the deposition amount was evaluated by measuring the stable Cs remaining on leaf. In the presentation, we will discuss the detail

  14. The Effect of Ultrafine Aerosol (0.5 to 50 NM (0.05 Micrometers)) on the Deposition of Radon Progeny in Human Lungs and Implications for the Measurement of Exposure.

    NASA Astrophysics Data System (ADS)

    Schmalbeck, Linda Michaels

    1995-01-01

    Despite a generally acknowledged public health risk from indoor exposure to airborne radon progeny, measurement techniques in current use do not provide sufficient information to assess risk from exposures in the home. By contrast, a simple, direct, measurement (the working level month) is a reliable starting point for the evaluation of miners' risks from radon progeny exposure. Ultrafine particles (0.5 to 50 nm in diameter) are frequently present in room air, especially during high occupancy times when activities like cooking and cleaning are taking place; but they are virtually absent from mine air. Measurement techniques used to evaluate mine and indoor air exposures do not supply any size-based data. Few studies of ultrafine aerosol deposition in humans have been undertaken, and none of these has specifically examined ultrafine particle deposition in the radiosensitive bronchial region of the respiratory tract. In this research, the effect of ultrafine aerosol on radon progeny deposition in the bronchial airways was studied using: (1) a unique human exposure data base involving 8 men and 4 women volunteers, (2) a mathematical model describing the attachment behavior of radon progeny in the presence of aerosol developed as part of this work, and (3) a human respiratory-tract deposition model. The addition of ultrafine aerosol to the air breathed by human subjects more than doubled the amount of radon progeny activity deposited in the bronchial region of the subjects' lungs, although radon gas concentration was held constant during all exposure experiments. The gamma activity measured in vivo remained higher at all times after exposure to ultrafine aerosol, while the rate of gamma activity clearance from the region was, on average, about 40 percent faster following ultrafine aerosol exposure. The human exposure data demonstrated that some aerosol size information is crucial to the determination of regional lung deposition and, consequently, the calculation of

  15. Improving aerosol interaction with clouds and precipitation in a regional chemical weather modeling system

    NASA Astrophysics Data System (ADS)

    Zhou, C.; Zhang, X.; Gong, S.; Wang, Y.; Xue, M.

    2016-01-01

    A comprehensive aerosol-cloud-precipitation interaction (ACI) scheme has been developed under a China Meteorological Administration (CMA) chemical weather modeling system, GRAPES/CUACE (Global/Regional Assimilation and PrEdiction System, CMA Unified Atmospheric Chemistry Environment). Calculated by a sectional aerosol activation scheme based on the information of size and mass from CUACE and the thermal-dynamic and humid states from the weather model GRAPES at each time step, the cloud condensation nuclei (CCN) are interactively fed online into a two-moment cloud scheme (WRF Double-Moment 6-class scheme - WDM6) and a convective parameterization to drive cloud physics and precipitation formation processes. The modeling system has been applied to study the ACI for January 2013 when several persistent haze-fog events and eight precipitation events occurred.

    The results show that aerosols that interact with the WDM6 in GRAPES/CUACE obviously increase the total cloud water, liquid water content, and cloud droplet number concentrations, while decreasing the mean diameters of cloud droplets with varying magnitudes of the changes in each case and region. These interactive microphysical properties of clouds improve the calculation of their collection growth rates in some regions and hence the precipitation rate and distributions in the model, showing 24 to 48 % enhancements of threat score for 6 h precipitation in almost all regions. The aerosols that interact with the WDM6 also reduce the regional mean bias of temperature by 3 °C during certain precipitation events, but the monthly means bias is only reduced by about 0.3 °C.

  16. Impact of Interactive Aerosol on the African Easterly Jet in the NASA GEOS-5 Global Forecasting System

    NASA Technical Reports Server (NTRS)

    Reale, O.; Lau, K. M.; da Silva, A.

    2010-01-01

    The real-time treatment of interactive realistically varying aerosol in a global operational forecasting system, as opposed to prescribed (fixed or climatologically varying) aerosols, is a very difficult challenge that only recently begins to be addressed. Experiment results from a recent version of the NASA GEOS-5 forecasting system, inclusive of interactive aerosol treatment, are presented in this work. Four sets of 30 5-day forecasts are initialized from a high quality set of analyses previously produced and documented to cover the period from 15 August to 16 September 2006, which corresponds to the NASA African Monsoon Multidisciplinary Analysis (NAMMA) observing campaign. The four forecast sets are at two different horizontal resolutions and with and without interactive aerosol treatment. The net impact of aerosol, at times in which there is a strong dust outbreak, is a temperature increase at the dust level and decrease in the near-surface levels, in complete agreement with previous observational and modeling studies. Moreover, forecasts in which interactive aerosols are included depict an African Easterly (AEJ) at slightly higher elevation, and slightly displace northward, with respect to the forecasts in which aerosols are not include. The shift in the AEJ position goes in the direction of observations and agrees with previous results.

  17. Aerosol generation and characterization of multi-walled carbon nanotubes exposed to cells cultured at the air-liquid interface.

    PubMed

    Polk, William W; Sharma, Monita; Sayes, Christie M; Hotchkiss, Jon A; Clippinger, Amy J

    2016-04-23

    Aerosol generation and characterization are critical components in the assessment of the inhalation hazards of engineered nanomaterials (NMs). An extensive review was conducted on aerosol generation and exposure apparatus as part of an international expert workshop convened to discuss the design of an in vitro testing strategy to assess pulmonary toxicity following exposure to aerosolized particles. More specifically, this workshop focused on the design of an in vitro method to predict the development of pulmonary fibrosis in humans following exposure to multi-walled carbon nanotubes (MWCNTs). Aerosol generators, for dry or liquid particle suspension aerosolization, and exposure chambers, including both commercially available systems and those developed by independent researchers, were evaluated. Additionally, characterization methods that can be used and the time points at which characterization can be conducted in order to interpret in vitro exposure results were assessed. Summarized below is the information presented and discussed regarding the relevance of various aerosol generation and characterization techniques specific to aerosolized MWCNTs exposed to cells cultured at the air-liquid interface (ALI). The generation of MWCNT aerosols relevant to human exposures and their characterization throughout exposure in an ALI system is critical for extrapolation of in vitro results to toxicological outcomes in humans.

  18. Desktop exposure system and dosimetry for small scale in vivo radiofrequency exposure experiments.

    PubMed

    Gong, Yijian; Capstick, Myles; Tillmann, Thomas; Dasenbrock, Clemens; Samaras, Theodoros; Kuster, Niels

    2016-01-01

    This paper describes a new approach to the risk assessment of exposure from wireless network devices, including an exposure setup and dosimetric assessment for in vivo studies. A novel desktop reverberation chamber has been developed for well-controlled exposure of mice for up to 24 h per day to address the biological impact of human exposure scenarios by wireless networks. The carrier frequency of 2.45 GHz corresponds to one of the major bands used in data communication networks and is modulated by various modulation schemes, including Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Radio Frequency Identification (RFID), and wireless local area network, etc. The system has been designed to enable exposures of whole-body averaged specific absorption rate (SAR) of up to 15 W/kg for six mice of an average weight of 25 g or of up to 320 V/m incident time-averaged fields under loaded conditions without distortion of the signal. The dosimetry for whole-body SAR and organ-averaged SAR of the exposed mice, with analysis of uncertainty and variation analysis, is assessed. The experimental dosimetry based on temperature measurement agrees well with the numerical dosimetry, with a very good SAR uniformity of 0.4 dB in the chamber. Furthermore, a thermal analysis and measurements were performed to provide better understanding of the temperature load and distribution in the mice during exposure.

  19. Desktop exposure system and dosimetry for small scale in vivo radiofrequency exposure experiments.

    PubMed

    Gong, Yijian; Capstick, Myles; Tillmann, Thomas; Dasenbrock, Clemens; Samaras, Theodoros; Kuster, Niels

    2016-01-01

    This paper describes a new approach to the risk assessment of exposure from wireless network devices, including an exposure setup and dosimetric assessment for in vivo studies. A novel desktop reverberation chamber has been developed for well-controlled exposure of mice for up to 24 h per day to address the biological impact of human exposure scenarios by wireless networks. The carrier frequency of 2.45 GHz corresponds to one of the major bands used in data communication networks and is modulated by various modulation schemes, including Global System for Mobile Communications (GSM), Universal Mobile Telecommunications System (UMTS), Radio Frequency Identification (RFID), and wireless local area network, etc. The system has been designed to enable exposures of whole-body averaged specific absorption rate (SAR) of up to 15 W/kg for six mice of an average weight of 25 g or of up to 320 V/m incident time-averaged fields under loaded conditions without distortion of the signal. The dosimetry for whole-body SAR and organ-averaged SAR of the exposed mice, with analysis of uncertainty and variation analysis, is assessed. The experimental dosimetry based on temperature measurement agrees well with the numerical dosimetry, with a very good SAR uniformity of 0.4 dB in the chamber. Furthermore, a thermal analysis and measurements were performed to provide better understanding of the temperature load and distribution in the mice during exposure. PMID:26769169

  20. Interesting Scientific Questions Regarding Interactions in the Gas-aerosol-cloud System

    NASA Technical Reports Server (NTRS)

    Tabazadeh, Azadeh

    2002-01-01

    The growth of human population and their use of land, food and energy resources affect the Earth's atmosphere, biosphere and oceans in a complex manner. Many important questions in earth sciences today deal with issues regarding the impact of human activities on our immediate and future environment, ranging in scope from local (i.e. air pollution) to global (i.e. global warming) scale problems. Because the mass of the Earth's atmosphere is negligible compare to that found in the oceans and the biosphere, the atmosphere can respond quickly to natural and/or manmade perturbations. For example, seasonal 'ozone hole' formation in the Antarctic is a result of manmade CFC emissions in just the last 40 years. Also, the observed rise in global temperatures (known as global warming) is linked to a rapid increase in carbon dioxide and other greenhouse gas concentrations (emitted primarily by combustion processes) over the last century. The Earth's atmosphere is composed of a mixture of gases, aerosol and cloud particles. Natural and anthropogenic emissions of gases and aerosols affect the composition of the Earth's atmosphere. Changes in the chemical and physical makeup of the atmosphere can influence how the Earth will interact with the incoming solar radiation and the outgoing infrared radiation and vise versa. While, some perturbations are short-lived, others are long-lived and can affect the Earth's global climate and chemistry in many decades to come, In order to be able to separate the natural effects from anthropogenic ones, it is essential that we understand the basic physics and chemistry of interactions in the gas-aerosol-cloud system in the Earth's atmosphere. The important physics and chemistry that takes place in the coupled gas-aerosol-cloud system as it relates to aircraft observations are discussed.

  1. Evaluation of systems for reducing the transmission of porcine reproductive and respiratory syndrome virus by aerosol.

    PubMed

    Dee, Scott A; Batista, Laura; Deen, John; Pijoan, Carlos

    2006-01-01

    The purpose of this study was to compare 3 methods for the reduction of aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV): high-efficiency particulate air (HEPA) filtration, low-cost filtration, and ultraviolet light (UV) irradiation. The HEPA-filtration system involved a pre-filter screen, a bag filter (EU8 rating), and a HEPA filter (EU13 rating). The low-cost-filtration system contained mosquito netting (pre-filter), a fiberglass furnace filter, and an electrostatic furnace filter. For UV irradiation, a lamp emitted UVC radiation at 253.7 nm. No form of intervention was used in the control group. The experimental facilities consisted of 2 chambers connected by a 1.3-m-long duct. Recipient pigs, housed in chamber 2, were exposed to artificial aerosols created by a mechanically operated mister containing modified live PRRSV vaccine located in chamber 1. Aerosol transmission of PRRSV occurred in 9 of the 10 control replicates, 8 of the 10 UVC-irradiation replicates, 4 of the 10 low-cost-filtration replicates, and 0 of the 10 HEPA-filtration replicates. When compared with no intervention, HEPA filtration and low-cost filtration significantly reduced PRRSV transmission (P < 0.0005 and = 0.0286, respectively), whereas UV irradiation had no effect (P = 0.5). However, low-cost filtration and UV irradiation were significantly less effective (P = 0.043 and P < 0.0005, respectively) than HEPA filtration. In conclusion, under the conditions of this study, HEPA filtration was significantly more effective at reducing aerosol transmission of PRRSV than the other methods evaluated. PMID:16548329

  2. Tropospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Buseck, P. R.; Schwartz, S. E.

    2003-12-01

    m, PM10=1.1 μg m-3; estimated coefficient of light scattering by particulate matter, σep, at 570 nm=12 Mm-1). (b) High aerosol concentration (PM2.5=43.9 μg m-3; PM10=83.4 μg m-3; estimated σep at 570 nm=245 Mm-1) (reproduced by permission of National Park Service, 2002). Although comprising only a small fraction of the mass of Earth's atmosphere, aerosol particles are highly important constituents of the atmosphere. Special interest has focused on aerosols in the troposphere, the lowest part of the atmosphere, extending from the land or ocean surface typically to ˜8 km at high latitudes, ˜12 km in mid-latitudes, and ˜16 km at low latitudes. That interest arises in large part because of the importance of aerosol particles in geophysical processes, human health impairment through inhalation, environmental effects through deposition, visibility degradation, and influences on atmospheric radiation and climate.Anthropogenic aerosols are thought to exert a substantial influence on Earth's climate, and the need to quantify this influence has sparked much of the current interest in and research on tropospheric aerosols. The principal mechanisms by which aerosols influence the Earth radiation budget are scattering and absorbing solar radiation (the so-called "direct effects") and modifying clouds and precipitation, thereby affecting both radiation and hydrology (the so-called "indirect effects"). Light scattering by aerosols increases the brightness of the planet, producing a cooling influence. Light-absorbing aerosols such as black carbon exert a warming influence. Aerosols increase the reflectivity of clouds, another cooling influence. These radiative influences are quantified as forcings, where a forcing is a perturbation to the energy balance of the atmosphere-Earth system, expressed in units of watts per square meter, W m-2. A warming influence is denoted a positive forcing, and a cooling influence, negative. The radiative direct and indirect forcings by

  3. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets.

  4. [Development and Performance Evaluation of a Supermicron Particle Generation System for Aerosol Instrument Calibration].

    PubMed

    Chen, Xiao-tong; Jiang, Jing-kun; Deng, Jian-guo; Duan, Lei; Hao, Ji-ming

    2016-03-15

    Accurate calibration of aerosol measurement instruments is critical for ensuring the data quality when sampling ambient particulate matter (PM) or those from emission sources. A system for calibrating these instruments was set up, which included an ultrasonic device to generate polydisperse supermicron particles, a chamber, and an aerodynamic particle spectrometer to measure particle size distribution. We verified its performance in stably generated testing aerosol with good spatial uniformity, controlled size distributions and concentrations. The testing aerosol generated had a lognormal distribution. A PM₁₀ and PM₂.₅ two-stage virtual impactor was calibrated using this online method. Collection efficiencies of PM₁₀ and PM₂.₅ stages calibrated by an off-line method using monodisperse particles were also used for comparison. The results from two different methods were consistent with each other. Though the off-line method has been widely used to calibrate PM samplers, it suffers from long experimental duration (2-3 days for calibrating one sampler). In contrast, the online method allows for a rapid calibration (less than half a day for calibrating one sampler). PMID:27337867

  5. Methods for measuring performance of vehicle cab air cleaning systems against aerosols and vapours.

    PubMed

    Bémer, D; Subra, I; Régnier, R

    2009-06-01

    Vehicle cabs equipped with an effective air cleaning and pressurization system, fitted to agricultural and off-road machineries, isolate drivers from the polluted environment, in which they are likely to work. These cabs provide protection against particulate and gaseous pollutants generated by these types of work activities. Two laboratory methods have been applied to determining the performance characteristics of two cabs of different design, namely, optical counting-based measurement of a potassium chloride (KCl) aerosol and fluorescein aerosol-based tracing. Results of cab confinement efficiency measurements agreed closely for these two methods implemented in the study. Measurements showed that high confinement efficiencies can be achieved with cabs, which are properly designed in ventilation/cleaning/airtightness terms. We also noted the importance of filter mounting airtightness, in which the smallest defect is reflected by significant degradation in cab performance. Determination of clean airflow rate by monitoring the decrease in test aerosol concentration in the test chamber gave excellent results. This method could represent an attractive alternative to methods involving gas tracing or air velocity measurement at blowing inlets. PMID:19406910

  6. Attempts to counteract phosgene-induced acute lung injury by instant high-dose aerosol exposure to hexamethylenetetramine, cysteine or glutathione.

    PubMed

    Pauluhn, Jürgen; Hai, Chun Xue

    2011-01-01

    Phosgene is an important high-production-volume intermediate with widespread industrial use. Consistent with other lung irritants causing ALI (acute lung injury), mode-of-action-based countermeasures remain rudimentary. This study was conducted to analyze whether extremely short high-level exposure to phosgene gas could be mitigated using three different inhaled nucleophiles administered by inhalation instantly after exposure to phosgene. Groups of young adult male Wistar rats were acutely exposed to carbonyl chloride (phosgene) using a directed-flow nose-only mode of exposure of 600 mg/m³ for 1.5 min (225 ppm × min). Immediately after exposure to phosgene gas the rats were similarly exposed to three strong nucleophiles with and without antioxidant properties for 5 or 15 min. The following nucleophiles were used: hexamethylenetetramine (HMT), l-cysteine (Cys), and l-glutathione (GSH). The concentration of the aerosol (mass median aerodynamic diameter 1.7-2 µm) was targeted to be in the range of 1 mg/L. Cys and GSH have antioxidant properties in addition. The calculated alveolar molar dosage of phosgene was 9 µmol/kg. At 15-min exposure duration, the respective inhaled dose of HMT, Csy, and GSH were 111, 103, and 46 µmol/kg, respectively. The alveolar dose of drugs was ~10-times lower. The efficacy of treatment was judged by protein concentrations in bronchoalveolar lavage fluid (BALF) collected 1 day post-exposure. In spite of using optimized aerosolization techniques, none of the nucleophiles chosen had any mitigating effect on BALF-protein extravasation. This finding appear to suggest that inhaled phosgene gas acylates instantly nucleophilic moieties at the site of initial deposition and that the resultant reaction products can not be reactivated even following instant inhalation treatment with competing nucleophilic agents. In spite of using maximal technically attainable concentrations, it appears to be experimentally challenging to deliver

  7. Generation and Characterization of Indoor Fungal Aerosols for Inhalation Studies

    PubMed Central

    Larsen, Søren T.; Koponen, Ismo K.; Kling, Kirsten I.; Barooni, Afnan; Karottki, Dorina Gabriela; Tendal, Kira; Wolkoff, Peder

    2016-01-01

    In the indoor environment, people are exposed to several fungal species. Evident dampness is associated with increased respiratory symptoms. To examine the immune responses associated with fungal exposure, mice are often exposed to a single species grown on an agar medium. The aim of this study was to develop an inhalation exposure system to be able to examine responses in mice exposed to mixed fungal species aerosolized from fungus-infested building materials. Indoor airborne fungi were sampled and cultivated on gypsum boards. Aerosols were characterized and compared with aerosols in homes. Aerosols containing 107 CFU of fungi/m3 air were generated repeatedly from fungus-infested gypsum boards in a mouse exposure chamber. Aerosols contained Aspergillus nidulans, Aspergillus niger, Aspergillus ustus, Aspergillus versicolor, Chaetomium globosum, Cladosporium herbarum, Penicillium brevicompactum, Penicillium camemberti, Penicillium chrysogenum, Penicillium commune, Penicillium glabrum, Penicillium olsonii, Penicillium rugulosum, Stachybotrys chartarum, and Wallemia sebi. They were all among the most abundant airborne species identified in 28 homes. Nine species from gypsum boards and 11 species in the homes are associated with water damage. Most fungi were present as single spores, but chains and clusters of different species and fragments were also present. The variation in exposure level during the 60 min of aerosol generation was similar to the variation measured in homes. Through aerosolization of fungi from the indoor environment, cultured on gypsum boards, it was possible to generate realistic aerosols in terms of species composition, concentration, and particle sizes. The inhalation-exposure system can be used to study responses to indoor fungi associated with water damage and the importance of fungal species composition. PMID:26921421

  8. A study of aerosol optical properties using a lightweight optical particle spectrometer and sun photometer from an unmanned aerial system

    NASA Astrophysics Data System (ADS)

    Telg, H.; Murphy, D. M.; Bates, T. S.; Johnson, J. E.; Gao, R. S.

    2015-12-01

    A miniaturized printed optical particle spectrometer (POPS) and sun photometer (miniSASP) have been developed recently for unmanned aerial systems (UAS) and balloon applications. Here we present the first scientific data recorded by the POPS and miniSASP from a Manta UAS during a field campaign on Svalbard, Norway, in April 2015. As part of a payload composed of five different aerosol instruments (absorption photometer, condensation particle counter, filter sampler, miniSASP and POPS) we collected particle size distributions, the optical depth (OD) and the sky brightness from 0 to 3000 m altitude. The complementary measurement approaches of the miniSASP and POPS allow us to calculate aerosol optical properties such as the aerosol optical depth and the angstrom exponent or the asymmetry parameter independently. We discuss deviation between results with respect to aerosol properties, e.g. hygroscopicity and absorption, as well as instrumental limitations.

  9. A new modeling system for studying aerosol - cloud -radiation interaction processes

    NASA Astrophysics Data System (ADS)

    Solomos, S.; Kallos, G.; Kuhsta, J.; Tremback, C.

    2008-12-01

    Links and feedbacks between air pollution and climate are complicated and are not accurately described in existing atmospheric models. In an attempt to better understand such links and feedbacks the new Integrated Community Limited Area Modeling System - ICLAMS has been developed. ICLAMS is an enhanced version of RAMS.6 modeling system. It includes submodels for the dust and sea salt cycles, gas and aqueous phase chemistry, gas to particle conversion and heterogeneous chemistry processes. All these processes are directly coupled with meteorology. RAMS has an explicit cloud microphysical scheme with eight categories of hydrometeors. The photochemical processes are directly linked to the RAMS radiative transfer scheme. The system is capable to be configured on two-way interactive nesting with any number of nested grids with resolution ranging from tens of kilometers to a few tens of meters. The system has been developed to study air pollution transport and transformation processes in the Greater Euro-Mediterranean Region and East Atlantic. This area is well known for its regional characteristics where the mixture of different age of anthropogenic air pollutants with Saharan dust and sea salt may lead to the formation of other particles with different characteristics. The mixture of the aerosols and gases from anthropogenic and natural origin (desert dust and sea salt) results in the formation of new types of PM with different physico-chemical properties and especially hygroscopicity (e.g. inside clouds or within the marine boundary layer) through heterogeneous processes. In this presentation, we demonstrate the transport and transformation processes at various spatiotemporal scales and discuss implications related to aerosol composition and their impacts on clouds and radiation (CCN and IN formation). We discuss the composition of the aerosols in the atmosphere along the long paths from Europe to North Africa and Atlantic. The composition changes and therefore the

  10. UV-LED exposure system for low-cost photolithography

    NASA Astrophysics Data System (ADS)

    Yapici, Murat Kaya; Farhat, Ilyas

    2014-03-01

    This paper reports the development of a low-cost, portable, light-emitting diode (LED)-based UV exposure system for photolithography. The major system components include UV-LEDs, microcontroller, digital-to-analog (D/A) converter and LED control circuitry. The UV-LED lithography system is also equipped with a digital user interface (LCD and keypad) and permits accurate electronic control on the exposure time and power. Hence the exposure dose can be varied depending on process requirements. Compared to traditional contact lithography, the UV-LED lithography system is significantly cheaper, simple to construct using off-the shelf components and does not require complex infrastructure to operate. Such reduction in system cost and complexity renders UV-LED lithography as a perfect candidate for micro lithography with large process windows typically suitable for MEMS, microfluidics applications.

  11. Nd:YAG and ruby based lidar systems for remote sensing of atmospheric aerosols

    NASA Technical Reports Server (NTRS)

    Fuller, W. H., Jr.

    1985-01-01

    The application of solid-state lasers to the study of stratospheric and tropospheric aerosols is analyzed. A 48-inch mobile lidar which operates in the 0.6943, 1.06, 0.3472, and 0.5300 micron ranges is utilized to monitor the stratosphere. The detectors of the system consist of photomultipliers, and the dual-channel, computer-based data-acquisition-system which provides on-line plotting of scattering ratio profiles. The components of the 14-inch aperture, dual-wavelength airborne lidar system that operates with ruby and Nd:YAG transmitters are described. An 8-inch, down-looking airborne lidar with silicon diode or photomultiplier detectors was developed. The capabilities of the system alone and when combined with the 14-inch lidar are discussed. Examples of the data provided by the three lidar systems are presented, revealing the reliability and operational efficiency of the systems.

  12. Gene Expression and Pulmonary Toxicity of Chitosan-graft- Polyethylenimine as Aerosol Gene Carrier.

    PubMed

    Kwon, Jung-Taek; Jiang, Hu-Lin; Minai-Tehrani, Arash; Gyu Woo, Chang; Choi, Mansoo; Cho, Chong-Su; Kim, Yeon-Soo; Cho, Myung-Haing

    2013-01-01

    Chitosan-graft-polyethylenimine (CHI-g-PEI) copolymer has been used for the improvement of low transfection efficiency of chitosan. The present study aims to test the pulmonary toxicity and efficiency of CHI-g-PEI as an aerosol gene carrier. Mice were exposed to aerosol containing green-fluorescent protein (GFP)-polyethylenimine (PEI) or GFP-CHI-g-PEI complexes for 30 min during the development of our nose-only exposure chamber (NOEC) system. CHI-g-PEI-mediated aerosol delivery demonstrated 15.65% enhancement of the fluorescence intensity. Compared to PEI, CHI-g-PEI showed no significant pulmonary toxicity. In summary, using CHI-g-PEI is safe and shows high transfection in aerosol gene delivery to animals, and enhanced efficiency was achieved through our aerosol gene delivery system. Therefore, CHI-g-PEI and this system would be applicable to future study for aerosol gene therapy. PMID:24250601

  13. Airborne water vapor DIAL system and measurements of water and aerosol profiles

    NASA Technical Reports Server (NTRS)

    Higdon, Noah S.; Browell, Edward V.

    1991-01-01

    The Lidar Applications Group at NASA Langley Research Center has developed a differential absorption lidar (DIAL) system for the remote measurement of atmospheric water vapor (H2O) and aerosols from an aircraft. The airborne H2O DIAL system is designed for extended flights to perform mesoscale investigations of H2O and aerosol distributions. This DIAL system utilizes a Nd:YAG-laser-pumped dye laser as the off-line transmitter and a narrowband, tunable Alexandrite laser as the on-line transmitter. The dye laser has an oscillator/amplifier configuration which incorporates a grating and prism in the oscillator cavity to narrow the output linewidth to approximately 15 pm. This linewidth can be maintained over the wavelength range of 725 to 730 nm, and it is sufficiently narrow to satisfy the off-line spectral requirements. In the Alexandrite laser, three intracavity tuning elements combine to produce an output linewidth of 1.1 pm. These spectral devices include a five-plate birefringent tuner, a 1-mm thick solid etalon and a 1-cm air-spaced etalon. A wavelength stability of +/- 0.35 pm is achieved by active feedback control of the two Fabry-Perot etalons using a frequency stabilized He-Ne laser as a wavelength reference. The three tuning elements can be synchronously scanned over a 150 pm range with microprocessor-based scanning electronics. Other aspects of the DIAL system are discussed.

  14. Ontic Occlusion and Exposure in Sociotechnical Systems

    ERIC Educational Resources Information Center

    Knobel, Cory Philip

    2010-01-01

    Living inside built environments--infrastructure--it is easy to take for granted the things that we do not need to engage, but are at work behind the scenes nonetheless. Well-designed systems become invisible, but to engage them, how do we know which perspectives, objects, and relationships are useful? I examine the University of Michigan Digital…

  15. Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System.

    PubMed

    Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Noh, Jung-Hun; Yook, Se-Jin; Cho, So-Hye; Bae, Gwi-Nam

    2015-01-01

    Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2 nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD). PMID:26125024

  16. Workplace Exposure to Titanium Dioxide Nanopowder Released from a Bag Filter System

    PubMed Central

    Ji, Jun Ho; Kim, Jong Bum; Lee, Gwangjae; Noh, Jung-Hun; Yook, Se-Jin; Cho, So-Hye; Bae, Gwi-Nam

    2015-01-01

    Many researchers who use laboratory-scale synthesis systems to manufacture nanomaterials could be easily exposed to airborne nanomaterials during the research and development stage. This study used various real-time aerosol detectors to investigate the presence of nanoaerosols in a laboratory used to manufacture titanium dioxide (TiO2). The TiO2 nanopowders were produced via flame synthesis and collected by a bag filter system for subsequent harvesting. Highly concentrated nanopowders were released from the outlet of the bag filter system into the laboratory. The fractional particle collection efficiency of the bag filter system was only 20% at particle diameter of 100 nm, which is much lower than the performance of a high-efficiency particulate air (HEPA) filter. Furthermore, the laboratory hood system was inadequate to fully exhaust the air discharged from the bag filter system. Unbalanced air flow rates between bag filter and laboratory hood systems could result in high exposure to nanopowder in laboratory settings. Finally, we simulated behavior of nanopowders released in the laboratory using computational fluid dynamics (CFD). PMID:26125024

  17. Rapid-response, light-exposure control system

    NASA Technical Reports Server (NTRS)

    Kuehl, D. K.; Zwillenberg, M. L.

    1968-01-01

    Rapid-response electro-optical, light exposure control system, will maintain the light reaching a camera film or other light-sensitive detector at essentially constant level, despite wide variations in the brightness of the light source. The system permits detailed photographic or photoelectric recording of the phenomenon over a range of brightnesses.

  18. Systemic Microvascular Dysfunction and Inflammation after Pulmonary Particulate Matter Exposure

    PubMed Central

    Nurkiewicz, Timothy R.; Porter, Dale W.; Barger, Mark; Millecchia, Lyndell; Rao, K. Murali K.; Marvar, Paul J.; Hubbs, Ann F.; Castranova, Vincent; Boegehold, Matthew A.

    2006-01-01

    The epidemiologic association between pulmonary exposure to ambient particulate matter (PM) and cardiovascular dysfunction is well known, but the systemic mechanisms that drive this effect remain unclear. We have previously shown that acute pulmonary exposure to PM impairs or abolishes endothelium-dependent arteriolar dilation in the rat spinotrapezius muscle. The purpose of this study was to further characterize the effect of pulmonary PM exposure on systemic microvascular function and to identify local inflammatory events that may contribute to these effects. Rats were intratracheally instilled with residual oil fly ash (ROFA) or titanium dioxide at 0.1 or 0.25 mg/rat 24 hr before measurement of pulmonary and systemic microvascular responses. In vivo microscopy of the spinotrapezius muscle was used to study systemic arteriolar responses to intraluminal infusion of the Ca2+ ionophore A23187 or iontophoretic abluminal application of the adrenergic agonist phenylephrine (PHE). Leukocyte rolling and adhesion were quantified in venules paired with the studied arterioles. Histologic techniques were used to assess pulmonary inflammation, characterize the adherence of leukocytes to systemic venules, verify the presence of myeloperoxidase (MPO) in the systemic microvascular wall, and quantify systemic microvascular oxidative stress. In the lungs of rats exposed to ROFA or TiO2, changes in some bronchoalveolar lavage markers of inflammation were noted, but an indication of cellular damage was not found. In rats exposed to 0.1 mg ROFA, focal alveolitis was evident, particularly at sites of particle deposition. Exposure to either ROFA or TiO2 caused a dose-dependent impairment of endothelium-dependent arteriolar dilation. However, exposure to these particles did not affect microvascular constriction in response to PHE. ROFA and TiO2 exposure significantly increased leukocyte rolling and adhesion in paired venules, and these cells were positively identified as

  19. Systemic microvascular dysfunction and inflammation after pulmonary particulate matter exposure.

    PubMed

    Nurkiewicz, Timothy R; Porter, Dale W; Barger, Mark; Millecchia, Lyndell; Rao, K Murali K; Marvar, Paul J; Hubbs, Ann F; Castranova, Vincent; Boegehold, Matthew A

    2006-03-01

    The epidemiologic association between pulmonary exposure to ambient particulate matter (PM) and cardiovascular dysfunction is well known, but the systemic mechanisms that drive this effect remain unclear. We have previously shown that acute pulmonary exposure to PM impairs or abolishes endothelium-dependent arteriolar dilation in the rat spinotrapezius muscle. The purpose of this study was to further characterize the effect of pulmonary PM exposure on systemic microvascular function and to identify local inflammatory events that may contribute to these effects. Rats were intratracheally instilled with residual oil fly ash (ROFA) or titanium dioxide at 0.1 or 0.25 mg/rat 24 hr before measurement of pulmonary and systemic microvascular responses. In vivo microscopy of the spinotrapezius muscle was used to study systemic arteriolar responses to intraluminal infusion of the Ca2+ ionophore A23187 or iontophoretic abluminal application of the adrenergic agonist phenylephrine (PHE). Leukocyte rolling and adhesion were quantified in venules paired with the studied arterioles. Histologic techniques were used to assess pulmonary inflammation, characterize the adherence of leukocytes to systemic venules, verify the presence of myeloperoxidase (MPO) in the systemic microvascular wall, and quantify systemic microvascular oxidative stress. In the lungs of rats exposed to ROFA or TiO2, changes in some bronchoalveolar lavage markers of inflammation were noted, but an indication of cellular damage was not found. In rats exposed to 0.1 mg ROFA, focal alveolitis was evident, particularly at sites of particle deposition. Exposure to either ROFA or TiO2 caused a dose-dependent impairment of endothelium-dependent arteriolar dilation. However, exposure to these particles did not affect microvascular constriction in response to PHE. ROFA and TiO2 exposure significantly increased leukocyte rolling and adhesion in paired venules, and these cells were positively identified as

  20. Radiation internal exposure measurements archiving system (REMAS).

    PubMed

    Bitar, A; Maghrabi, M

    2013-12-01

    This paper describes a personal-computer-based software, REMAS, which helps users to estimate intake activity and resulting internal doses for all radionuclides existing in (International Commission on Radiological Protection) ICRP 78 and other important elements. In addition to its use in internal dose calculations, it facilitates management of data of monitored persons who are occupationally exposed to unsealed radioactive substances. Furthermore, REMAS offers the possibility to generate different reports of results. The program is suitable for laboratories working in the field of assessment of occupational intake and also for users of radioactive material who are routinely monitored. REMAS, which is bilingual program (English and Arabic), was built with GUI environment and was developed using Microsoft FoxPro. It runs on Microsoft Windows XP operating systems.

  1. Radiation internal exposure measurements archiving system (REMAS).

    PubMed

    Bitar, A; Maghrabi, M

    2013-12-01

    This paper describes a personal-computer-based software, REMAS, which helps users to estimate intake activity and resulting internal doses for all radionuclides existing in (International Commission on Radiological Protection) ICRP 78 and other important elements. In addition to its use in internal dose calculations, it facilitates management of data of monitored persons who are occupationally exposed to unsealed radioactive substances. Furthermore, REMAS offers the possibility to generate different reports of results. The program is suitable for laboratories working in the field of assessment of occupational intake and also for users of radioactive material who are routinely monitored. REMAS, which is bilingual program (English and Arabic), was built with GUI environment and was developed using Microsoft FoxPro. It runs on Microsoft Windows XP operating systems. PMID:23782905

  2. A dichotomy in primary marine organic aerosol-cloud-climate system

    NASA Astrophysics Data System (ADS)

    Ceburnis, D.; Ovadnevaite, J.; Martucci, G.; Bialek, J.; Monahan, C.; Rinaldi, M.; Facchini, C.; Berresheim, H.; Worsnop, D. R.; O'Dowd, C.

    2011-12-01

    D. Ceburnis1, J. Ovadnevaite1, G. Martucci1, J. Bialek1, C. Monahan1, M. Rinaldi2, M. C. Facchini2, H. Berresheim1, D. R. Worsnop3,4 and C. D. O'Dowd1 1School of Physics & Centre for Climate and Air Pollution Studies, National University of Ireland Galway, University Road, Galway, Ireland 2Institute of Atmospheric Sciences and Climate, National Research Council, Bologna, 20129, Italy. 3 Aerodyne Research, Inc., 45 Manning Road, Billerica, MA 01821-3976, USA 4 Physics Department, University of Helsinki, P.O. Box 64, 00014, Helsinki, Finland Organic matter has been observed to significantly contribute to particulate matter in every environment including pristine remote oceans. A significant if not dominant contribution of insoluble organic matter to marine aerosol has been proved to be of biogenic origin1,2. High time resolution measurements of marine organic matter have demonstrated a dynamic system with regular organic matter plume events occurring during summer3 as well as frequent open ocean particle formation events4. High-time resolution measurements of primary marine organic sea-spray physico-chemical properties reveal an apparent dichotomous behavior in terms of water uptake: specifically sea-spray aerosol enriched in organic matter possesses a low hygroscopic Growth Factor (GF~1.25) while simultaneously having a cloud condensation nucleus/condensation nuclei (CCN/CN) activation efficiency of between 83% at 0.25% supersaturation and 100% at 0.75%5. Simultaneous retrieval of Cloud Droplet Number Concentration (CDNC) during primary organic aerosol plumes reveal CDNC concentrations of 350 cm-3 in newly formed marine stratocumulus cloud for boundary layer organic mass concentrations of 3-4 ug m-36. It is suggested that marine hydrogels are responsible for this dichotomous behavior which has profound impacts to aerosol-cloud-climate system along with a better understood process analysis of aerosol formation by sea-spray7. A hydrophobic character of organic matter

  3. Design, construction, and characterization of a novel robotic welding fume generator and inhalation exposure system for laboratory animals.

    PubMed

    Antonini, James M; Afshari, Aliakbar A; Stone, Sam; Chen, Bean; Schwegler-Berry, Diane; Fletcher, W Gary; Goldsmith, W Travis; Vandestouwe, Kurt H; McKinney, Walter; Castranova, Vincent; Frazer, David G

    2006-04-01

    Respiratory effects observed in welders have included lung function changes, metal fume fever, bronchitis, and a possible increase in the incidence of lung cancer. Many questions remain unanswered regarding the causality and possible underlying mechanisms associated with the potential toxic effects of welding fume inhalation. The objective of the present study was to construct a completely automated, computer-controlled welding fume generation and inhalation exposure system to simulate real workplace exposures. The system comprised a programmable six-axis robotic welding arm, a water-cooled arc welding torch, and a wire feeder that supplied the wire to the torch at a programmed rate. For the initial studies, gas metal arc welding was performed using a stainless steel electrode. A flexible trunk was attached to the robotic arm of the welder and was used to collect and transport fume from the vicinity of the arc to the animal exposure chamber. Undiluted fume concentrations consistently ranged from 90-150 mg/m(3) in the animal chamber during welding. Temperature and humidity remained constant in the chamber during the welding operation. The welding particles were composed of (from highest to lowest concentration) iron, chromium, manganese, and nickel as measured by inductively coupled plasma atomic emission spectroscopy. Size distribution analysis indicated the mass median aerodynamic diameter of the generated particles to be approximately 0.24 microm with a geometric standard deviation (sigma(g)) of 1.39. As determined by transmission and scanning electron microscopy, the generated aerosols were mostly arranged as chain-like agglomerates of primary particles. Characterization of the laboratory-generated welding aerosol has indicated that particle morphology, size, and chemical composition are comparable to stainless steel welding fume generated in other studies. With the development of this novel system, it will be possible to establish an animal model using

  4. Measurement of tropospheric aerosol in São Paulo area using a new upgraded Raman LIDAR system

    NASA Astrophysics Data System (ADS)

    Landulfo, Eduardo; Rodrigues, Patrícia F.; da Silva Lopes, Fábio Juliano; Bourayou, Riad

    2012-11-01

    Elastic backscatter LIDAR systems have been used to determine aerosol profile concentration in several areas such as weather, pollution and air quality monitoring. In order to determine the aerosol extinction and backscattering profiles, the Klett inversion method is largely used, but this method suffers from lack of information since there are two unknown variables to be determined using only one measured LIDAR signal, and assumption of the LIDAR ratio (the relation between the extinction and backscattering coefficients) is needed. When a Raman LIDAR system is used, the inelastic backscattering signal is affected by aerosol extinction but not by aerosol backscatter, which allows this LIDAR to uniquely determine extinction and backscattering coefficients without any assumptions or any collocated instruments. The MSP-LIDAR system, set-up in a highly dense suburban area in the city of São Paulo, has been upgraded to a Raman LIDAR, and in its actual 6-channel configuration allows it to monitor elastic backscatter at 355 and 532 nm together with nitrogen and water vapor Raman backscatters at 387nm and 608 nm and 408nm and 660 nm, respectively. Thus, the measurements of aerosol backscattering, extinction coefficients and water vapor mixing ratio in the Planetary Boundary Layer (PBL) are becoming available. The system will provide the important meteorological parameters such as Aerosol Optical Depth (AOD) and will be used for the study of aerosol variations in lower troposphere over the city of São Paulo, air quality monitoring and for estimation of humidity impact on the aerosol optical properties, without any a priori assumption. This study will present the first results obtained with this upgraded LIDAR system, demonstrating the high quality of obtained aerosol and water vapor data. For that purpose, we compared the data obtained with the new MSP-Raman LIDAR with a mobile Raman LIDAR collocated at the Center for Lasers and Applications, Nuclear and Energy Research

  5. Multifunctional SMA-based smart inhaler system for improved aerosol drug delivery: design and fabrication

    NASA Astrophysics Data System (ADS)

    Pausley, Matthew E.; Seelecke, Stefan

    2008-03-01

    This paper documents the development of a prototype smart aerosol drug inhaler system using shape memory alloy (SMA) actuators. Unlike conventional dispersed-release inhalers, the smart inhaler system releases the aerosol drug in a very small area within the mouth inlet. Kleinstreuer and Zhang [1] have found that controlled release in the mouth inlet increases drug efficiency and allows targeting of specific sites within the lung. The methodology has been validated numerically and experimentally using fixed-exit position inhalers. The design presented in this work, however, allows for variation of nozzle exit position using SMA wire actuators in a combined actuator/sensor role. In contrast to other possible mechanisms, SMA wires are lightweight, require low power, and are the least obstructive to the flow of air through the inhaler. The dual actuator/sensor nature of the SMA wires (via resistance measurement) further simplifies the design. Solutions and insights into several SMA actuator design challenges are presented. SMA wire actuator characteristics such as achievable stroke and their effect on the design are highlighted. Consideration of actuator force requirements and the capabilities of SMA wires and studied. The problems posed by the thermal characteristics of SMA wires and innovative solutions are reported.

  6. The Cloud-Aerosol Transport System (CATS): A New Earth Science Capability for ISS (Invited)

    NASA Astrophysics Data System (ADS)

    McGill, M. J.; Yorks, J. E.; Scott, S.; Kupchock, A.; Selmer, P.

    2013-12-01

    The Cloud-Aerosol Transport System (CATS) is a lidar remote sensing instrument developed for deployment to the International Space Station (ISS). The CATS lidar will provide range-resolved profile measurements of atmospheric aerosol and cloud distributions and properties. The CATS instrument uses a high repetition rate laser operating at three wavelengths (1064, 532, and 355 nm) to derive properties of cloud/aerosol layers including: layer height, layer thickness, backscatter, optical depth, extinction, and depolarization-based discrimination of particle type. The CATS mission was designed to capitalize on the Space Station's unique orbit and facilities to continue existing Earth Science data records, to provide observational data for use in forecast models, and to demonstrate new technologies for use in future missions. The CATS payload will be installed on the Japanese Experiment Module - Exposed Facility (JEM-EF). The payload is designed to operate on-orbit for at least six months, and up to three years. The payload is completed and currently scheduled for a mid-2014 launch. The ISS and, in particular, the JEM-EF, is an exciting new platform for spaceborne Earth observations. The ability to leverage existing aircraft instrument designs coupled with the lower cost possible for ISS external attached payloads permits rapid and cost effective development of spaceborne sensors. The CATS payload is based on existing instrumentation built and operated on the high-altitude NASA ER-2 aircraft. The payload is housed in a 1.5 m x 1 m x 0.8 m volume that attaches to the JEM-EF. The allowed volume limits the maximum size for the collecting telescope to 60 cm diameter. Figure 1 shows a schematic layout of the CATS payload, with the primary instrument components identified. Figure 2 is a photo of the completed payload. CATS payload cut-away view. Completed CATS payload assembly.

  7. GUIDE TO CALCULATING TRANSPORT EFFICIENCY OF AEROSOLS IN OCCUPATIONAL AIR SAMPLING SYSTEMS

    SciTech Connect

    Hogue, M.; Hadlock, D.; Thompson, M.; Farfan, E.

    2013-11-12

    This report will present hand calculations for transport efficiency based on aspiration efficiency and particle deposition losses. Because the hand calculations become long and tedious, especially for lognormal distributions of aerosols, an R script (R 2011) will be provided for each element examined. Calculations are provided for the most common elements in a remote air sampling system, including a thin-walled probe in ambient air, straight tubing, bends and a sample housing. One popular alternative approach would be to put such calculations in a spreadsheet, a thorough version of which is shared by Paul Baron via the Aerocalc spreadsheet (Baron 2012). To provide greater transparency and to avoid common spreadsheet vulnerabilities to errors (Burns 2012), this report uses R. The particle size is based on the concept of activity median aerodynamic diameter (AMAD). The AMAD is a particle size in an aerosol where fifty percent of the activity in the aerosol is associated with particles of aerodynamic diameter greater than the AMAD. This concept allows for the simplification of transport efficiency calculations where all particles are treated as spheres with the density of water (1g cm-3). In reality, particle densities depend on the actual material involved. Particle geometries can be very complicated. Dynamic shape factors are provided by Hinds (Hinds 1999). Some example factors are: 1.00 for a sphere, 1.08 for a cube, 1.68 for a long cylinder (10 times as long as it is wide), 1.05 to 1.11 for bituminous coal, 1.57 for sand and 1.88 for talc. Revision 1 is made to correct an error in the original version of this report. The particle distributions are based on activity weighting of particles rather than based on the number of particles of each size. Therefore, the mass correction made in the original version is removed from the text and the calculations. Results affected by the change are updated.

  8. Impacts of the direct radiative effect of aerosols in numerical weather prediction over Europe using the ALADIN-HIRLAM NWP system

    NASA Astrophysics Data System (ADS)

    Toll, V.; Gleeson, E.; Nielsen, K. P.; Männik, A.; Mašek, J.; Rontu, L.; Post, P.

    2016-05-01

    Aerosol feedbacks are becoming more accepted as physical mechanisms that should be included in numerical weather prediction models in order to improve the accuracy of the weather forecasts. The default set-up in the Aire Limitee Adaptation dynamique Developpement INternational (ALADIN) - High Resolution Limited Area Model (HIRLAM) numerical weather prediction system includes monthly aerosol climatologies to account for the average direct radiative effect of aerosols. This effect was studied using the default aerosol climatology in the system and compared to experiments run using the more up-to-date Max-Planck-Institute Aerosol Climatology version 1 (MACv1), and time-varying aerosol data from the Monitoring Atmospheric Composition and Climate (MACC) reanalysis aerosol dataset. Accounting for the direct radiative effect using monthly aerosol climatologies or near real-time aerosol distributions improved the accuracy of the simulated radiative fluxes and temperature and humidity forecasts in the lower troposphere. However, the dependency of forecast meteorological conditions on the aerosol dataset itself was found to be weak.

  9. A lidar system for remote sensing of aerosols and water vapor from NSTS and Space Station Freedom

    NASA Technical Reports Server (NTRS)

    Delorme, Joseph F.

    1989-01-01

    The Tropical Atmospheric Lidar Observing System (TALOS) is proposed to be developed as a Differential Absorption Lidar (DIAL) system for flight aboard the earth orbiting Space Station Freedom. TALOS will be capable of making high resolution vertical profile measurements of tropospheric water and tropospheric and stratospheric aerosols, clouds and temperature.

  10. [Aerosol therapy].

    PubMed

    Wildhaber, J H

    1998-08-15

    Aerosol therapy plays a major role in the diagnosis and treatment of various lung diseases. The aim of inhalation therapy is to deposit a reproducible and adequate dose of a specific drug to the airways, in order to achieve a high, local, clinical effect while avoiding serious systemic side effects. To achieve this goal, it is therefore important to have an efficient inhalation device to deliver different medications. However, the currently available therapeutic inhalation devices (nebuliser, pressurised metered-dose inhaler and dry powder inhaler) are not very efficient in aerosol delivery and have several disadvantages. Inhalation devices can be assessed by in vitro studies, filter studies and radiolabelled deposition studies. Several radiolabelled deposition studies have shown that nebulisers and pressurised metered-dose inhalers are not very efficient in aerosol delivery. In children, before 1997, only 0.5% to 15% of the total nebulised or actuated dose from a nebuliser or pressurised metered-dose inhaler actually reached the lungs. These numbers were somewhat improved in adults, 30% of the total nebulised or actuated dose reaching the airways. Aerosol therapy with dry powder inhalers was the most efficient before 1997, 30% of the total dose being deposited in the lungs of adults and children. In 1997, new developments in pressurised metered-dose inhalers much improved their efficiency in aerosol delivery. Lung deposition can be increased by up to 60% with use of a non-electrostatic holding chamber and/or a pressurised metered-dose inhaler with a hydrofluoroalkane propellant possessing superior aerosol characteristics. Several studies comparing the clinical efficiency of different inhalation devices have shown that the choice of an optimal inhalation device is crucial. In addition to the aerosol characteristics, ventilation parameters and airway morphology have an important bearing on deposition patterns. These parameters may be greatly influenced by the

  11. A consistent prescription of stratospheric aerosol for both radiation and chemistry in the Community Earth System Model (CESM1)

    NASA Astrophysics Data System (ADS)

    Reynolds Neely, Ryan, III; Conley, Andrew J.; Vitt, Francis; Lamarque, Jean-François

    2016-07-01

    Here we describe an updated parameterization for prescribing stratospheric aerosol in the National Center for Atmospheric Research (NCAR) Community Earth System Model (CESM1). The need for a new parameterization is motivated by the poor response of the CESM1 (formerly referred to as the Community Climate System Model, version 4, CCSM4) simulations contributed to the Coupled Model Intercomparison Project 5 (CMIP5) to colossal volcanic perturbations to the stratospheric aerosol layer (such as the 1991 Pinatubo eruption or the 1883 Krakatau eruption) in comparison to observations. In particular, the scheme used in the CMIP5 simulations by CESM1 simulated a global mean surface temperature decrease that was inconsistent with the GISS Surface Temperature Analysis (GISTEMP), NOAA's National Climatic Data Center, and the Hadley Centre of the UK Met Office (HADCRUT4). The new parameterization takes advantage of recent improvements in historical stratospheric aerosol databases to allow for variations in both the mass loading and size of the prescribed aerosol. An ensemble of simulations utilizing the old and new schemes shows CESM1's improved response to the 1991 Pinatubo eruption. Most significantly, the new scheme more accurately simulates the temperature response of the stratosphere due to local aerosol heating. Results also indicate that the new scheme decreases the global mean temperature response to the 1991 Pinatubo eruption by half of the observed temperature change, and modelled climate variability precludes statements as to the significance of this change.

  12. Assessing the Cytotoxicity of Black Carbon As A Model for Ultrafine Anthropogenic Aerosol Across Human and Murine Cells: A Chronic Exposure Model of Nanosized Particulate Matter

    NASA Astrophysics Data System (ADS)

    Salinas, E.

    2015-12-01

    Combustion-derived nanomaterials or ultrafine (<1 μm) atmospheric aerosols are primarily products of anthropogenic activities, such as the burning of fossil fuels. Ultrafine particles (UFPs) can absorb other noxious pollutants including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), toxic organic compounds, and heavy metals. The combination of high population density, meteorological conditions, and industrial productivity brings high levels of air pollution to the metropolitan area of El Paso, Texas, USA/ Ciudad Juarez, Chihuahua, Mexico, comprising the Paso del Norte air basin. A study conducted by scientists from the Research Triangle Park in North Carolina, analyzed sites adjacent to heavy-traffic highways in El Paso and elucidated higher UFP concentrations in comparison to previously published work exploring pollution and adverse health effects in the basin. UFPs can penetrate deep into the alveolar sacs of the lung, reaching distant alveolar sacs and inducing a series of immune responses that are detrimental to the body: evidence suggests that UFPs can also cross the alveolar-blood barrier and potentially endanger the body's immune response. The physical properties of UFPs and the dynamics of local atmospheric and topographical conditions indicate that emissions of nanosized carbonaceous aerosols could pose significant threats to biological tissues upon inhalation by local residents of the Paso del Norte. This study utilizes Black Carbon (BC) as a model for environmental UFPs and its effects on the immunological response. An in vitro approach is used to measure the ability of BC to promote cell death upon long-term exposure. Human epithelial lung cells (A549), human peripheral-blood monocytes (THP-1), murine macrophages (RAW264.7), and murine epithelial lung cells (LA-4) were treated with BC and assessed for metabolic activity after chronic exposure utilizing three distinct and independent cell viability assays. The cell viability

  13. Sensitization of the Trigeminovascular System following Environmental Irritant Exposure

    PubMed Central

    Kunkler, Phillip Edward; Zhang, LuJuan; Pellman, Jessica Joan; Oxford, Gerry Stephen; Hurley, Joyce Harts

    2016-01-01

    Background Air pollution is linked to increased emergency room visits for headache and migraine patients frequently cite chemicals or odors as headache triggers, but the association between air pollutants and headache is not well-understood. We previously reported that nasal administration of environmental irritants acutely increases meningeal blood flow via a TRPA1-dependent mechanism, involving the trigeminovascular system. Here, we examine whether chronic environmental irritant exposure sensitizes the trigeminovascular system. Methods Male rats were exposed to acrolein, a TRPA1 agonist, or room air by inhalation for 4 days prior to meningeal blood flow measurements. Some animals were injected daily with a TRPA1 antagonist, AP-18 or vehicle prior to inhalation exposure. Trigeminal ganglia were isolated following blood flow measurements for immunocytochemistry and/or qPCR determination of TRPV1, TRPA1 and CGRP levels. Results Acrolein inhalation exposure potentiated blood flow responses to both TRPA1 and TRPV1 agonists compared to room air. Acrolein exposure did not alter TRPV1 or TRPA1 mRNA levels or TRPV1 or CGRP immunoreactive cell counts in the trigeminal ganglion. Acrolein sensitization of trigeminovascular responses to a TRPA1 agonist was attenuated by pre-treatment with AP-18. Interpretation These results suggest trigeminovascular sensitization as a mechanism for enhanced headache susceptibility after chemical exposure. PMID:25724913

  14. Aerosol sampling and Transport Efficiency Calculation (ASTEC) and application to surtsey/DCH aerosol sampling system: Code version 1. 0: Code description and user's manual

    SciTech Connect

    Yamano, N.; Brockmann, J.E.

    1989-05-01

    This report describes the features and use of the Aerosol Sampling and Transport Efficiency Calculation (ASTEC) Code. The ASTEC code has been developed to assess aerosol transport efficiency source term experiments at Sandia National Laboratories. This code also has broad application for aerosol sampling and transport efficiency calculations in general as well as for aerosol transport considerations in nuclear reactor safety issues. 32 refs., 31 figs., 7 tabs.

  15. Projected response of East Asian summer monsoon system to future reductions in emissions of anthropogenic aerosols and their precursors

    NASA Astrophysics Data System (ADS)

    Wang, Zhili; Zhang, Hua; Zhang, Xiaoye

    2016-09-01

    The response of the East Asian summer monsoon (EASM) system to reductions in emissions of anthropogenic aerosols and their precursors at the end of the twenty-first century projected by Representative Concentration Pathway 4.5 is studied using an aerosol-climate model with aerosol direct, semi-direct, and indirect effects included. Our results show that the global annual mean aerosol effective radiative forcing at the top of the atmosphere (TOA) is +1.45 W m-2 from 2000 to 2100. The summer mean net all-sky shortwave fluxes averaged over the East Asian monsoon region (EAMR) at the TOA and surface increased by +3.9 and +4.0 W m-2, respectively, due to the reductions of aerosols in 2100 relative to 2000. Changes in radiations affect local thermodynamic and dynamic processes and the hydrological cycle. The summer mean surface temperature and pressure averaged over the EAMR are shown to increase by 1.7 K and decreased by 0.3 hPa, respectively, due to the reduced aerosols. The magnitudes of these changes are larger over land than ocean, causing a marked increase in the contrast of land-sea surface temperature and pressure in the EAMR, thus strengthening the EASM. The summer mean southwest and south winds at 850 hPa are enhanced over eastern and southern China and the surrounding oceans, and the East Asian subtropical jet shifted northward due to the decreases of aerosols. These factors also indicate enhanced EASM circulation, which in turn causes a 10 % increase in summer mean precipitation averaged over the EAMR.

  16. The customised electronic nebuliser: a new category of liquid aerosol drug delivery systems.

    PubMed

    Knoch, Martin; Keller, Manfred

    2005-03-01

    Inhalation of aerosols is the preferred route of administration of pharmaceutical compounds to the lungs when treating various respiratory diseases. Inhaled antibiotics, hormones, peptides and proteins are potential candidates for direct targeting to the site of action, thus minimising systemic absorption, dilution and undesired side effects, as much lower doses (as low as a fiftieth) are sufficient to achieve a similar therapeutic effect, compared with oral administration. A quick relief from the symptoms and a good tolerance are the main advantages of aerosol therapy. A new class of electronic delivery device is now starting to enter the market. The eFlow electronic nebuliser (PARI GmbH, Germany) provides improved portability and, in some instances, cuts treatment time to only a fraction of what has been experienced with current nebulised therapy. Drug formulations and the device can be mutually adapted and matched for optimal characteristics to meet the desired therapeutic target. Reformulation of known and proven compounds in a liquid format are commercially attractive as they present a relatively low development risk for potential drug candidates and, thus, have become a preferred pathway for the development of new inhalation products. PMID:16296761

  17. Global Lidar Measurements of Clouds and Aerosols from Space Using the Geoscience Laser Altimeter System (GLAS)

    NASA Technical Reports Server (NTRS)

    Hlavka, Dennis L.; Palm, S. P.; Welton, E. J.; Hart, W. D.; Spinhirne, J. D.; McGill, M.; Mahesh, A.; Starr, David OC. (Technical Monitor)

    2001-01-01

    The Geoscience Laser Altimeter System (GLAS) is scheduled for launch on the ICESat satellite as part of the NASA EOS mission in 2002. GLAS will be used to perform high resolution surface altimetry and will also provide a continuously operating atmospheric lidar to profile clouds, aerosols, and the planetary boundary layer with horizontal and vertical resolution of 175 and 76.8 m, respectively. GLAS is the first active satellite atmospheric profiler to provide global coverage. Data products include direct measurements of the heights of aerosol and cloud layers, and the optical depth of transmissive layers. In this poster we provide an overview of the GLAS atmospheric data products, present a simulated GLAS data set, and show results from the simulated data set using the GLAS data processing algorithm. Optical results from the ER-2 Cloud Physics Lidar (CPL), which uses many of the same processing algorithms as GLAS, show algorithm performance with real atmospheric conditions during the Southern African Regional Science Initiative (SAFARI 2000).

  18. Inter-comparison of laboratory smog chamber and flow reactor systems on organic aerosol yield and composition

    NASA Astrophysics Data System (ADS)

    Bruns, E. A.; El Haddad, I.; Keller, A.; Klein, F.; Kumar, N. K.; Pieber, S. M.; Corbin, J. C.; Slowik, J. G.; Brune, W. H.; Baltensperger, U.; Prévôt, A. S. H.

    2015-06-01

    A variety of tools are used to simulate atmospheric aging, including smog chambers and flow reactors. Traditional, large-scale smog chambers age emissions over the course of hours to days, whereas flow reactors rapidly age emissions using high oxidant concentrations to reach higher degrees of oxygenation than typically attained in smog chamber experiments. The atmospheric relevance of the products generated under such rapid oxidation warrants further study. However, no previously published studies have compared the yields and chemical composition of products generated in flow reactors and smog chambers from the same starting mixture. The yields and composition of the organic aerosol formed from the photo-oxidation of α-pinene and of wood-combustion emissions in a smog chamber (SC) and two flow reactors: a potential aerosol mass reactor (PAM) and a micro-smog chamber (MSC), were determined using aerosol mass spectrometry. Reactants were sampled from the SC and aged in the MSC and the PAM using a range of hydroxyl radical (OH) concentrations and then photo-chemically aged in the SC. The chemical composition, as well as the maximum yields and emission factors, of the products in both the α-pinene and wood-combustion systems determined with the PAM and the SC agreed reasonably well. High OH exposures have been shown previously to lower yields by breaking carbon-carbon bonds and forming higher volatility species, which reside largely in the gas phase; however, fragmentation in the PAM was not observed. The yields determined using the PAM for the α-pinene system were slightly lower than in the SC, possibly from increased wall losses of gas phase species due to the higher surface area to volume ratios in the PAM, even when offset with better isolation of the sampled flow from the walls. The α-pinene SOA results for the MSC were not directly comparable, as particles were smaller than the optimal AMS transmission range. The higher supersaturation in the flow reactors

  19. A Miniature System for Separating Aerosol Particles and Measuring Mass Concentrations

    PubMed Central

    Liang, Dao; Shih, Wen-Pin; Chen, Chuin-Shan; Dai, Chi-An

    2010-01-01

    We designed and fabricated a new sensing system which consists of two virtual impactors and two quartz-crystal microbalance (QCM) sensors for measuring particle mass concentration and size distribution. The virtual impactors utilized different inertial forces of particles in air flow to classify different particle sizes. They were designed to classify particle diameter, d, into three different ranges: d < 2.28 μm, 2.28 μm ≤ d ≤ 3.20 μm, d > 3.20 μm. The QCM sensors were coated with a hydrogel, which was found to be a reliable adhesive for capturing aerosol particles. The QCM sensor coated with hydrogel was used to measure the mass loading of particles by utilizing its characteristic of resonant frequency shift. An integrated system has been demonstrated. PMID:22319317

  20. Plutonium-aerosol emission rates and potential inhalation exposure during cleanup and treatment test at Area 11, Nevada Test Site

    SciTech Connect

    Shinn, J.H.; Homan, D.N.

    1985-08-13

    A Cleanup and Treatment (CAT) test was conducted in 1981 at Area 11, Nevada Test Site. Its purpose was to evaluate the effectiveness of using a large truck-mounted vacuum cleaner similar to those used to clean paved streets for cleaning radiological contamination from the surface of desert soils. We found that four passes with the vehicle removed 97% of the alpha contamination and reduced resuspension by 99.3 to 99.7%. Potential exposure to cleanup workers was slight when compared to natural background exposure. 7 refs., 1 fig., 2 tabs.

  1. Optical design and development of the Near Range Lidar system for aerosol investigation at Belsk

    NASA Astrophysics Data System (ADS)

    Posyniak, Michal; Piatruczuk, Aleksander; Szkop, Artur

    2015-04-01

    The development of the lidar system in the Central Geophysics Observatory at Belsk (Poland) is presented. Belsk is an aerosol background site located in a rural area about 50 km south from Warsaw. A new near range (NR) lidar was added to the existing far range (FR) lidar system to enable the acquisition of lidar signals at the distance of a few hundred meters from the device. In the existing design of the FR lidar a 600 mm diameter mirror was used which resultedin anoverlap over 1500 mmaking this device suitable for observations of aerosols in free troposphere and lower stratosphere but not in the Planetary Boundary Layer (PBL).To enable measurements in the PBL the near range detection systemwas designed as a complement of the existing FR lidar. A secondtelescope with a set of detectors was used with the same laser as in the FR system as a light source. The Nd:YAGpulselasergenerates three wavelengths (1064, 532 and 355 nm).Energies of light pulses are about 320 mJ while their repetition rate is 15 Hz. In the optical receiver of the NR lidar a telescope with a 150 mm diameter parabolic mirror with optical fiber (1 mm core diameter) as a field stop was used. Our analysis shows that full overlap of the laser beam and the NR telescope field of view is expected at about 150 m. A polichromator based on dichroic beam splitters and a set of narrow band pass filters were used to separate wavelengths. The design of the NR lidar easily allows to add Raman channels to the system. The acquisition of the analog lidar echoes was done by photomultipliers (at 355 and 532 nm) and the avalanche photodiode (at 1064 nm). 14 bit analog to digital converters coupled with PC computer by USB 2.0 were also used.

  2. Interchangeable whole-body and nose-only exposure system

    DOEpatents

    Cannon, William C.; Allemann, Rudolph T.; Moss, Owen R.; Decker, Jr., John R.

    1992-01-01

    An exposure system for experimental animals includes a container for a single animal which has a double wall. The animal is confined within the inner wall. Gaseous material enters a first end, flows over the entire animal, then back between the walls and out the first end. The system also includes an arrangement of valve-controlled manifolds for supplying gaseous material to, and exhausting it from, the containers.

  3. Interchangeable whole-body and nose-only exposure system

    DOEpatents

    Cannon, W.C.; Allemann, R.T.; Moss, O.R.; Decker, J.R. Jr.

    1992-03-31

    An exposure system for experimental animals includes a container for a single animal which has a double wall. The animal is confined within the inner wall. Gaseous material enters a first end, flows over the entire animal, then back between the walls and out the first end. The system also includes an arrangement of valve-controlled manifolds for supplying gaseous material to, and exhausting it from, the containers. 6 figs.

  4. Clinical and virological dynamics of a serotype O 2010 South East Asia lineage foot-and-mouth disease virus in sheep using natural and simulated natural inoculation and exposure systems.

    PubMed

    Stenfeldt, Carolina; Pacheco, Juan M; Singanallur, Nagendrakumar B; Ferreira, Helena C de Carvalho; Vosloo, Wilna; Rodriguez, Luis L; Arzt, Jonathan

    2015-07-01

    Within-host infection dynamics of a recent field isolate of foot-and-mouth disease virus (FMDV), serotype O, topotype South East Asia, lineage Myamar'98 were evaluated in sheep using four different systems for virus exposure. Two novel, simulated natural, inoculation systems consisting of intra-nasopharyngeal (INP) deposition and aerosol inoculation were evaluated in comparison with two conventional systems: coronary band inoculation and direct contact exposure. All four exposure systems were efficient in generating consistently severe, generalized FMD with synchronous clinical characteristics within exposure groups, indicating that this Myanmar98 strain is highly virulent in sheep. Clinical and virological dynamics were similarly rapid following INP- and coronary band inoculation, with both systems leading to significantly earlier detection of virus shedding when compared to aerosol inoculation and contact exposure. The data presented herein support application of the two optimized simulated natural inoculation systems as valid alternatives to conventionally used exposure systems for studies of FMDV pathogenesis and vaccinology in sheep. Furthermore, the data suggest that targeted exposure of the ovine pharynx is highly efficient for generating consistent FMDV infection, which supports critical involvement of this anatomic region as a site of primary virus replication in sheep.

  5. Does the Sympathetic Nervous System Adapt to Chronic Altitude Exposure?

    PubMed

    Sander, Mikael

    2016-01-01

    During continued exposure to hypobaric hypoxia in acclimatizing lowlanders increasing norepinephrine levels indirectly indicate sympathoexcitation, and in a few subjects serial measurements have suggested some adaptation over time. A few studies have provided direct microneurographic evidence for markedly increased muscle sympathetic nervous activity (MSNA) after 1-50 days of exposure of lowlanders to altitudes of 4100-5260 m above sea level. Only one study has provided two MSNA-measurements over time (10 and 50 days) in altitude (4100 m above sea level) and continued robust sympathoexcitation without adaptation was found in acclimatizing lowlanders. In this study, norepinephrine levels during rest and exercise also remained highly elevated over time. In comparison, acute exposure to hypoxic breathing (FiO2 0.126) at sea level caused no change in sympathetic nervous activity, although the same oxygen saturation in arterial blood (around 90 %) was present during acute (FiO2 0.126) and chronic hypoxic exposure (4100 m above sea level). These findings strongly suggest that the chemoreflex-mechanisms underlying acute hypoxia-induced increases in MSNA are sensitized over time. Collectively, the MSNA data suggests that sensitization of the sympathoexcitatory chemoreflex is evident but not complete within the first 24 h, but is complete after 10 days of altitude exposure. After return from high altitude to sea level the MSNA remains significantly elevated for at least 5 days but completely normalized after 3 months. The few MSNA measurements in high altitude natives have documented high sympathetic activity in all subjects studied. Because serial measurements of MSNA in high altitude natives during sea level exposure are lacking, it is unclear whether the sympathetic nervous system have somehow adapted to lifelong altitude exposure. PMID:27343109

  6. Introducing Subgrid-scale Convective Cloud and Aerosol Interactions to the WRF-CMAQ Integrated Modeling System

    NASA Astrophysics Data System (ADS)

    Alapaty, K. V.; Yu, S.; Nolte, C. G.; Zhang, G. J.; Song, X.; Pleim, J.; Mathur, R.; Wong, D.

    2013-12-01

    Many regional and global climate models include aerosol indirect effects (AIE) on grid-scale/resolved clouds. However, the interaction between aerosols and convective clouds remains highly uncertain, as noted in the IPCC AR4 report. The objective of this work is to help fill in this scientific gap by including aerosol indirect effects on parameterized deep convection in the WRF-CMAQ integrated regional modeling system. This is accomplished by first incorporating a convective cloud microphysical scheme directly into a deep convection parameterization, and linking that microphysical scheme with aerosols predicted by the air quality model, CMAQ. To study the relative magnitudes of aerosol indirect forcing by grid- and subgrid-scale clouds, three numerical simulations (one with AIE on resolved clouds only, one with AIE on subgrid-scale clouds only, and one with AIE on both resolved and subgrid-scale clouds) are performed for the summer months (June, July, and August) of 2006 covering the continental US using 12 km grids. These results along with the comparisons of the simulated cloud micro- and macro-physical and radiation parameters as well as other meteorological parameters with observations and reanalysis products will be presented.

  7. Observations of Dust Using the NASA Geoscience Laser Altimeter System (GLAS): New New Measurements of Aerosol Vertical Distribution From Space

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth; Spinhirne, James D.; Palm, Steven P.; Hlavka, Dennis; Hart, William

    2003-01-01

    On January 12, 2003 NASA launched the first satellite-based lidar, the Geoscience Laser -Altimeter System (GLAS), onboard the ICESat spacecraft. The GLAS atmospheric measurements introduce a fundamentally new and important tool for understanding the atmosphere and climate. In the past, aerosols have only been studied from space using images gathered by passive sensors. Analysis of this passive data has lead to an improved understanding of aerosol properties, spatial distribution, and their effect on the earth's climate. However, these images do not show the aerosol's vertical distribution. As a result, a key piece of information has been missing. The measurements now obtained by GLAS will provide information on the vertical distribution of aerosols and clouds, and improve our ability to study their transport processes and aerosol-cloud interactions. Here we show an overview of GLAS, provide an update of its current status, and present initial observations of dust profiles. In particular, a strategy of characterizing the height profile of dust plumes over source regions will be presented.

  8. PERSONAL, RESIDENTIAL AND CENTRAL SITE PM MASS CONCENTRATIONS ASSOCIATED WITH THE DETROIT EXPOSURE AND AEROSOL RESEARCH STUDY ( DEARS )

    EPA Science Inventory

    The DEARS is a three year field monitoring study being performed by the US EPA's National Exposure Research Laboratory in the Detroit, Michigan area. Two years of monitoring have been completed and data from the first year of the study is currently being analyzed. This report ...

  9. Infrared sensor-based aerosol sanitization system for controlling Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on fresh produce.

    PubMed

    Kim, Sang-Oh; Ha, Jae-Won; Park, Ki-Hwan; Chung, Myung-Sub; Kang, Dong-Hyun

    2014-06-01

    An economical aerosol sanitization system was developed based on sensor technology for minimizing sanitizer usage, while maintaining bactericidal efficacy. Aerosol intensity in a system chamber was controlled by a position-sensitive device and its infrared value range. The effectiveness of the infrared sensor-based aerosolization (ISA) system to inactivate Escherichia coli O157:H7, Salmonella Typhimurium, and Listeria monocytogenes on spinach leaf surfaces was compared with conventional aerosolization (full-time aerosol treated), and the amount of sanitizer consumed was determined after operation. Three pathogens artificially inoculated onto spinach leaf surfaces were treated with aerosolized peracetic acid (400 ppm) for 15, 30, 45, and 60 min at room temperature (22 ± 2°C). Using the ISA system, inactivation levels of the three pathogens were equal or better than treatment with conventional full-time aerosolization. However, the amount of sanitizer consumed was reduced by ca. 40% using the ISA system. The results of this study suggest that an aerosol sanitization system combined with infrared sensor technology could be used for transportation and storage of fresh produce efficiently and economically as a practical commercial intervention. PMID:24853521

  10. Xenobiotic pulmonary exposure and systemic cardiovascular response via neurological links.

    PubMed

    Stapleton, Phoebe A; Abukabda, Alaeddin B; Hardy, Steven L; Nurkiewicz, Timothy R

    2015-11-15

    The cardiovascular response to xenobiotic particle exposure has been increasingly studied over the last two decades, producing an extraordinary scope and depth of research findings. With the flourishing of nanotechnology, the term "xenobiotic particles" has expanded to encompass not only air pollution particulate matter (PM) but also anthropogenic particles, such as engineered nanomaterials (ENMs). Historically, the majority of research in these fields has focused on pulmonary exposure and the adverse physiological effects associated with a host inflammatory response or direct particle-tissue interactions. Because these hypotheses can neither account entirely for the deleterious cardiovascular effects of xenobiotic particle exposure nor their time course, the case for substantial neurological involvement is apparent. Indeed, considerable evidence suggests that not only is neural involvement a significant contributor but also a reality that needs to be investigated more thoroughly when assessing xenobiotic particle toxicities. Therefore, the scope of this review is several-fold. First, we provide a brief overview of the major anatomical components of the central and peripheral nervous systems, giving consideration to the potential biologic targets affected by inhaled particles. Second, the autonomic arcs and mechanisms that may be involved are reviewed. Third, the cardiovascular outcomes following neurological responses are discussed. Lastly, unique problems, future risks, and hurdles associated with xenobiotic particle exposure are discussed. A better understanding of these neural issues may facilitate research that in conjunction with existing research, will ultimately prevent the untoward cardiovascular outcomes associated with PM exposures and/or identify safe ENMs for the advancement of human health. PMID:26386111

  11. Aerosol Emission Monitoring and Assessment of Potential Exposure to Multi-walled Carbon Nanotubes in the Manufacture of Polymer Nanocomposites.

    PubMed

    Thompson, Drew; Chen, Sheng-Chieh; Wang, Jing; Pui, David Y H

    2015-11-01

    Recent animal studies have shown that carbon nanotubes (CNTs) may pose a significant health risk to those exposed in the workplace. To further understand this potential risk, effort must be taken to measure the occupational exposure to CNTs. Results from an assessment of potential exposure to multi-walled carbon nanotubes (MWCNTs) conducted at an industrial facility where polymer nanocomposites were manufactured by an extrusion process are presented. Exposure to MWCNTs was quantified by the thermal-optical analysis for elemental carbon (EC) of respirable dust collected by personal sampling. All personal respirable samples collected (n = 8) had estimated 8-h time weighted average (TWA) EC concentrations below the limit of detection for the analysis which was about one-half of the recommended exposure limit for CNTs, 1 µg EC/m(3) as an 8-h TWA respirable mass concentration. Potential exposure sources were identified and characterized by direct-reading instruments and area sampling. Area samples analyzed for EC yielded quantifiable mass concentrations inside an enclosure where unbound MWCNTs were handled and near a pelletizer where nanocomposite was cut, while those analyzed by electron microscopy detected the presence of MWCNTs at six locations throughout the facility. Through size selective area sampling it was identified that the airborne MWCNTs present in the workplace were in the form of large agglomerates. This was confirmed by electron microscopy where most of the MWCNT structures observed were in the form of micrometer-sized ropey agglomerates. However, a small fraction of single, free MWCNTs was also observed. It was found that the high number concentrations of nanoparticles, ~200000 particles/cm(3), present in the manufacturing facility were likely attributable to polymer fumes produced in the extrusion process.

  12. Aerosol Emission Monitoring and Assessment of Potential Exposure to Multi-walled Carbon Nanotubes in the Manufacture of Polymer Nanocomposites

    PubMed Central

    Thompson, Drew; Chen, Sheng-Chieh; Wang, Jing; Pui, David Y.H.

    2015-01-01

    Recent animal studies have shown that carbon nanotubes (CNTs) may pose a significant health risk to those exposed in the workplace. To further understand this potential risk, effort must be taken to measure the occupational exposure to CNTs. Results from an assessment of potential exposure to multi-walled carbon nanotubes (MWCNTs) conducted at an industrial facility where polymer nanocomposites were manufactured by an extrusion process are presented. Exposure to MWCNTs was quantified by the thermal-optical analysis for elemental carbon (EC) of respirable dust collected by personal sampling. All personal respirable samples collected (n = 8) had estimated 8-h time weighted average (TWA) EC concentrations below the limit of detection for the analysis which was about one-half of the recommended exposure limit for CNTs, 1 µg EC/m3 as an 8-h TWA respirable mass concentration. Potential exposure sources were identified and characterized by direct-reading instruments and area sampling. Area samples analyzed for EC yielded quantifiable mass concentrations inside an enclosure where unbound MWCNTs were handled and near a pelletizer where nanocomposite was cut, while those analyzed by electron microscopy detected the presence of MWCNTs at six locations throughout the facility. Through size selective area sampling it was identified that the airborne MWCNTs present in the workplace were in the form of large agglomerates. This was confirmed by electron microscopy where most of the MWCNT structures observed were in the form of micrometer-sized ropey agglomerates. However, a small fraction of single, free MWCNTs was also observed. It was found that the high number concentrations of nanoparticles, ~200000 particles/cm3, present in the manufacturing facility were likely attributable to polymer fumes produced in the extrusion process. PMID:26209597

  13. Simultaneous control of phenanthrene and drought by dual exposure system: the degree of synergistic interactions in springtails was exposure dependent.

    PubMed

    Schmidt, Stine N; Holmstrup, Martin; Damgaard, Christian; Mayer, Philipp

    2014-08-19

    Organisms in the environment are exposed to multiple stressors. However, for terrestrial invertebrates, it remains difficult to study the effects of combined stressors under well-defined exposure conditions. Thus, the current study develops a new dual exposure system for the simultaneous and independent control of chemical and drought exposure in bioassays with terrestrial organisms: Passive dosing from silicone controlled the chemical activity of phenanthrene (chemical stress), while saline solutions controlled the water activity (drought stress) in the closed exposure system. The dual exposure system was then applied in a full factorial experiment with seven exposure levels (7(2)), which aimed at determining the combined effects of phenanthrene and drought on the survival of the terrestrial springtail Folsomia candida after 7 d exposure. Fitting an "independent action" model to the complete data set revealed statistically significant synergy between phenanthrene and drought (p < 0.0001). However, the degree of synergy was exposure dependent with some synergy at higher and only minor synergy at lower exposure levels. This emphasizes the need for taking exposure levels into account when extrapolating synergy observations from (eco)toxicological studies done at high exposure levels. PMID:24998522

  14. Prenatal Alcohol Exposure and the Developing Immune System.

    PubMed

    Gauthier, Theresa W

    2015-01-01

    Evidence from research in humans and animals suggest that ingesting alcohol during pregnancy can disrupt the fetal immune system and result in an increased risk of infections and disease in newborns that may persist throughout life. Alcohol may have indirect effects on the immune system by increasing the risk of premature birth, which itself is a risk factor for immune-related problems. Animal studies suggest that alcohol exposure directly disrupts the developing immune system. A comprehensive knowledge of the mechanisms underlying alcohol's effects on the developing immune system only will become clear once researchers establish improved methods for identifying newborns exposed to alcohol in utero.

  15. WRF-CMAQ two-way coupled system with aerosol feedback: software development and preliminary results

    NASA Astrophysics Data System (ADS)

    Wong, D. C.; Pleim, J.; Mathur, R.; Binkowski, F.; Otte, T.; Gilliam, R.; Pouliot, G.; Xiu, A.; Young, J. O.; Kang, D.

    2011-09-01

    Air quality models such as the EPA Community Multiscale Air Quality (CMAQ) require meteorological data as part of the input to drive the chemistry and transport simulation. The Meteorology-Chemistry Interface Processor (MCIP) is used to convert meteorological data into CMAQ-ready input. Key shortcoming of such one-way coupling include: excessive temporal interpolation of coarsely saved meteorological input and lack of feedback of atmospheric pollutant loading on simulated dynamics. We have developed a two-way coupled system to address these issues. A single source code principle was used to construct this two-way coupling system so that CMAQ can be consistently executed as a stand-alone model or part of the coupled system without any code changes; this approach eliminates maintenance of separate code versions for the coupled and uncoupled systems. The design also provides the flexibility to permit users: (1) to adjust the call frequency of WRF and CMAQ to balance the accuracy of the simulation versus computational intensity of the system, and (2) to execute the two-way coupling system with feedbacks to study the effect of gases and aerosols on short wave radiation and subsequent simulated dynamics. Details on the development and implementation of this two-way coupled system are provided. When the coupled system is executed without radiative feedback, computational time is virtually identical when using the Community Atmospheric Model (CAM) radiation option and a slightly increased (~8.5 %) when using the Rapid Radiative Transfer Model for GCMs (RRTMG) radiation option in the coupled system compared to the offline WRF-CMAQ system. Once the feedback mechanism is turned on, the execution time increases only slightly with CAM but increases about 60 % with RRTMG due to the use of a more detailed Mie calculation in this implementation of feedback mechanism. This two-way model with radiative feedback shows noticeably reduced bias in simulated surface shortwave radiation

  16. WRF-CMAQ two-way coupled system with aerosol feedback: software development and preliminary results

    NASA Astrophysics Data System (ADS)

    Wong, D. C.; Pleim, J.; Mathur, R.; Binkowski, F.; Otte, T.; Gilliam, R.; Pouliot, G.; Xiu, A.; Young, J. O.; Kang, D.

    2012-03-01

    Air quality models such as the EPA Community Multiscale Air Quality (CMAQ) require meteorological data as part of the input to drive the chemistry and transport simulation. The Meteorology-Chemistry Interface Processor (MCIP) is used to convert meteorological data into CMAQ-ready input. Key shortcoming of such one-way coupling include: excessive temporal interpolation of coarsely saved meteorological input and lack of feedback of atmospheric pollutant loading on simulated dynamics. We have developed a two-way coupled system to address these issues. A single source code principle was used to construct this two-way coupling system so that CMAQ can be consistently executed as a stand-alone model or part of the coupled system without any code changes; this approach eliminates maintenance of separate code versions for the coupled and uncoupled systems. The design also provides the flexibility to permit users: (1) to adjust the call frequency of WRF and CMAQ to balance the accuracy of the simulation versus computational intensity of the system, and (2) to execute the two-way coupling system with feedbacks to study the effect of gases and aerosols on short wave radiation and subsequent simulated dynamics. Details on the development and implementation of this two-way coupled system are provided. When the coupled system is executed without radiative feedback, computational time is virtually identical when using the Community Atmospheric Model (CAM) radiation option and a slightly increased (~8.5%) when using the Rapid Radiative Transfer Model for GCMs (RRTMG) radiation option in the coupled system compared to the offline WRF-CMAQ system. Once the feedback mechanism is turned on, the execution time increases only slightly with CAM but increases about 60% with RRTMG due to the use of a more detailed Mie calculation in this implementation of feedback mechanism. This two-way model with radiative feedback shows noticeably reduced bias in simulated surface shortwave radiation and

  17. Aerosol MTF revisited

    NASA Astrophysics Data System (ADS)

    Kopeika, Norman S.; Zilberman, Arkadi; Yitzhaky, Yitzhak

    2014-05-01

    Different views of the significance of aerosol MTF have been reported. For example, one recent paper [OE, 52(4)/2013, pp. 046201] claims that the aerosol MTF "contrast reduction is approximately independent of spatial frequency, and image blur is practically negligible". On the other hand, another recent paper [JOSA A, 11/2013, pp. 2244-2252] claims that aerosols "can have a non-negligible effect on the atmospheric point spread function". We present clear experimental evidence of common significant aerosol blur and evidence that aerosol contrast reduction can be extremely significant. In the IR, it is more appropriate to refer to such phenomena as aerosol-absorption MTF. The role of imaging system instrumentation on such MTF is addressed too.

  18. Multiple scattering of polarized light in atmosphere- ocean systems: Application to sensitivity analyses of aerosol polarimetry

    NASA Astrophysics Data System (ADS)

    Chowdhary, Jacek

    1999-09-01

    Sunlight scattered by small particles in the atmosphere becomes partially polarized, the degree and state of which are sensitive to the physical and chemical properties of these particles. The high accuracy with which these polarization quantities can be measured causes space-borne polarimetry to be a promising remote sensing tool for retrieving tropospheric aerosols, but it also imposes strong requirements on the accuracy and efficiency of the methods used to numerically study such data. Light reflected by the lower atmospheric boundary may, in addition, become highly polarized, necessitating a careful error analysis of the latter scattering contribution to the remotely sensed signal. Part I of this work focusses, on the former requirements for an atmosphere-ocean system, and discusses an approach for treating scattering of light by water body, ocean surface, and atmosphere together in one method while employing numerically efficient techniques for each of these three components. Benchmark results are provided with an accuracy of 5 decimals for the Stokes vectors of scattering contributions to internal and external fields, and we discuss typical features seen in the bidirectional behaviour of the latter contributions. In Part II, we investigate uncertainties in the reflection properties of the ocean system and the resulting variation in degree of linear polarization observed from space. Three sources of uncertainty are identified: oceanic foam, the ocean surface roughness, and underwater light scattering. The magnitude of the latter two sources are derived from current remote sensing capabilities to retrieve the surface windspeed and oceanic pigment concentration, respectively. Simulations are carried out for the visible and near infrared part of the spectrum and two aerosol models. Our analyses indicate that the use of a priori information on the state of the ocean can provide enough constraints for aerosol polarimetry to be sufficiently accurate for climate

  19. Design of an Unattended Environmental Aerosol Sampling and Analysis System for Gaseous Centrifuge Enrichment Plants

    SciTech Connect

    Anheier, Norman C.; Munley, John T.; Alexander, M. L.

    2011-07-19

    the in-facility misuse detection devices. Onsite environmental sample collection offers the ability to collect fleeting uranium hexafluoride emissions before they are lost to the ventilation system or before they disperse throughout the facility, to become deposited onto surfaces that are contaminated with background and historical production material. Onsite aerosol sample collection, combined with enrichment analysis, provides the unique ability to quickly detect stepwise enrichment level changes within the facility, leading to a significant strengthening of facility misuse deterence. We report in this paper our study of several GCEP environmental sample release scenarios and simulation results of a newly designed aerosol collection and particle capture system that is fully integrated with the Laser Ablation, Absorbance Ratio Spectrometry (LAARS) uranium particle enrichment analysis instrument that was developed at the Pacific Northwest National Laboratory.

  20. Direct and semi-direct aerosol radiative effect on the Mediterranean climate variability using a coupled regional climate system model

    NASA Astrophysics Data System (ADS)

    Nabat, Pierre; Somot, Samuel; Mallet, Marc; Sevault, Florence; Chiacchio, Marc; Wild, Martin

    2015-02-01

    A fully coupled regional climate system model (CNRM-RCSM4) has been used over the Mediterranean region to investigate the direct and semi-direct effects of aerosols, but also their role in the radiation-atmosphere-ocean interactions through multi-annual ensemble simulations (2003-2009) with and without aerosols and ocean-atmosphere coupling. Aerosols have been taken into account in CNRM-RCSM4 through realistic interannual monthly AOD climatologies. An evaluation of the model has been achieved, against various observations for meteorological parameters, and has shown the ability of CNRM-RCSM4 to reproduce the main patterns of the Mediterranean climate despite some biases in sea surface temperature (SST), radiation and cloud cover. The results concerning the aerosol radiative effects show a negative surface forcing on average because of the absorption and scattering of the incident radiation. The SW surface direct effect is on average -20.9 Wm-2 over the Mediterranean Sea, -14.7 Wm-2 over Europe and -19.7 Wm-2 over northern Africa. The LW surface direct effect is weaker as only dust aerosols contribute (+4.8 Wm-2 over northern Africa). This direct effect is partly counterbalanced by a positive semi-direct radiative effect over the Mediterranean Sea (+5.7 Wm-2 on average) and Europe (+5.0 Wm-2) due to changes in cloud cover and atmospheric circulation. The total aerosol effect is consequently negative at the surface and responsible for a decrease in land (on average -0.4 °C over Europe, and -0.5 °C over northern Africa) and sea surface temperature (on average -0.5 °C for the Mediterranean SST). In addition, the latent heat loss is shown to be weaker (-11.0 Wm-2) in the presence of aerosols, resulting in a decrease in specific humidity in the lower troposphere, and a reduction in cloud cover and precipitation. Simulations also indicate that dust aerosols warm the troposphere by absorbing solar radiation, and prevent radiation from reaching the surface, thus

  1. Generation of tailored aerosols for inhalative drug delivery employing recent vibrating-mesh nebulizer systems.

    PubMed

    Bohr, Adam; Beck-Broichsitter, Moritz

    2015-01-01

    Direct drug delivery to the lungs is considered the gold standard for the treatment of a variety of respiratory diseases, owing to the increased therapeutic selectivity of the inhalative approach. Airborne formulations with defined size characteristics are required to improve the deposition pattern within the airways. In this respect, different nebulizer systems have been conceived, which has enabled the generation of respirable medicament mists. Here, vibrating-mesh technology revealed significant potential to overcome the main shortcomings associated with 'traditional' devices. Tailored orifice dimensions and defined formulation characteristics are of special interest for the generation of suitable aerosol droplets for inhalative purposes. Ongoing developments in device and formulation design will optimize the clinical outcome of inhalative drug delivery under application of vibrating-mesh technology.

  2. The Cloud-Aerosol Transport System (CATS): a technology demonstration on the International Space Station

    NASA Astrophysics Data System (ADS)

    McGill, Matthew J.; Yorks, John E.; Scott, V. S.; Kupchock, Andrew W.; Selmer, Patrick A.

    2015-09-01

    The Cloud-Aerosol Transport System (CATS) is a multi-wavelength lidar instrument developed to enhance Earth Science remote sensing capabilities from the International Space Station. The CATS project was chartered to be an experiment in all senses: science, technology, and management. As a low-cost project following a strict build-to-cost/ build-to-schedule philosophy, CATS is following a new management approach while also serving as a technology demonstration for future NASA missions. This presentation will highlight the CATS instrument and science objectives with emphasis on how the ISS platform enables the specific objectives of the payload. The development process used for CATS and a look at data being produced by the instrument will also be presented.

  3. Recent advances in the development of a novel aerosol sorting and deposition system for bio-threat sensing applications

    NASA Astrophysics Data System (ADS)

    Pletcher, Timothy; McGinn, Joseph; Keller, David; Huston, Alan; Eversole, Jay; Sivaprakasum, Vasanthi

    2007-10-01

    Sarnoff Corporation and the Naval Research Laboratory, through support of the U.S. Department of Homeland Security, are developing an automated, high throughput bio-aerosol physical enrichment system designed for use as part of a biological-threat protection system. The Biological Aerosol-Capture-Enrichment (BioACE) system is a bio-aerosol collection system that combines three unique technologies to create physically enriched aerosol samples that can be subsequently interrogated by any number of bio-threat detection systems for the presence of threat agents. An air-to-air concentrator uses an inertial separation technique to highly concentrate an aerosol sample presented to a dual wavelength ultra-violet laser induced fluorescence (UVLIF) optical trigger used to discriminate potential threat particles from non-threat particles conveyed in a collimated particle stream. This particle classification information is used to trigger an electrostatic deposition mechanism to deposit only those particles determined to be potential bio-threats onto a stainless steel substrate. Non-threat particles are discarded with the exiting airflow. The goal for the most recent development effort has been the integration and optimization of these technologies into a unit capable of producing highly enriched particulate samples from ambient air containing variable background aerosol loading and type. Several key technical and engineering challenges were overcome during the course of this development including a unique solution for compensating particle velocity dispersion within the airflow, development of a real-time signal acquisition and detection algorithm for determining material type on a particle by particle basis at rates greater than 2000 particles per second, and the introduction of a robust method for transferring deposited particulate into a 50ul wet sample suitable for most advanced bio-detection techniques. This paper will briefly describe the overall system architecture and

  4. Culture-Independent Analysis of Aerosol Microbiology in a Metropolitan Subway System

    PubMed Central

    Robertson, Charles E.; Baumgartner, Laura K.; Harris, J. Kirk; Peterson, Kristen L.; Stevens, Mark J.; Frank, Daniel N.

    2013-01-01

    The goal of this study was to determine the composition and diversity of microorganisms associated with bioaerosols in a heavily trafficked metropolitan subway environment. We collected bioaerosols by fluid impingement on several New York City subway platforms and associated sites in three sampling sessions over a 1.5-year period. The types and quantities of aerosolized microorganisms were determined by culture-independent phylogenetic analysis of small-subunit rRNA gene sequences by using both Sanger (universal) and pyrosequencing (bacterial) technologies. Overall, the subway bacterial composition was relatively simple; only 26 taxonomic families made up ∼75% of the sequences determined. The microbiology was more or less similar throughout the system and with time and was most similar to outdoor air, consistent with highly efficient air mixing in the system. Identifiable bacterial sequences indicated that the subway aerosol assemblage was composed of a mixture of genera and species characteristic of soil, environmental water, and human skin commensal bacteria. Eukaryotic diversity was mainly fungal, dominated by organisms of types associated with wood rot. Human skin bacterial species (at 99% rRNA sequence identity) included the Staphylococcus spp. Staphylococcus epidermidis (the most abundant and prevalent commensal of the human integument), S. hominis, S. cohnii, S. caprae, and S. haemolyticus, all well-documented human commensal bacteria. We encountered no organisms of public health concern. This study is the most extensive culture-independent survey of subway microbiota so far and puts in place pre-event information required for any bioterrorism surveillance activities or monitoring of the microbiological impact of recent subway flooding events. PMID:23542619

  5. Systems for animal exposure in full-scale fire tests

    NASA Technical Reports Server (NTRS)

    Hilado, C. J.; Cumming, H. J.; Kourtides, D. A.; Parker, J. A.

    1977-01-01

    Two systems for exposing animals in full-scale fire tests are described. Both systems involve the simultaneous exposure of two animal species, mice and rats, in modular units; determination of mortality, morbidity, and behavioral response; and analysis of the blood for carboxyhemoglobin. The systems described represent two of many possible options for obtaining bioassay data from full-scale fire tests. In situations where the temperatures to which the test animals are exposed can not be controlled, analytical techniques may be more appropriate than bioassay techniques.

  6. A Cough Aerosol Simulator for the Study of Disease Transmission by Human Cough-Generated Aerosols

    PubMed Central

    Lindsley, William G.; Reynolds, Jeffrey S.; Szalajda, Jonathan V.; Noti, John D.; Beezhold, Donald H.

    2015-01-01

    Aerosol particles expelled during human coughs are a potential pathway for infectious disease transmission. However, the importance of airborne transmission is unclear for many diseases. To better understand the role of cough aerosol particles in the spread of disease and the efficacy of different types of protective measures, we constructed a cough aerosol simulator that produces a humanlike cough in a controlled environment. The simulated cough has a 4.2 l volume and is based on coughs recorded from influenza patients. In one configuration, the simulator produces a cough aerosol containing particles from 0.1 to 100 µm in diameter with a volume median diameter (VMD) of 8.5 µm and a geometric standard deviation (GSD) of 2.9. In a second configuration, the cough aerosol has a size range of 0.1–30 µm, a VMD of 3.4 µm, and a GSD of 2.3. The total aerosol volume expelled during each cough is 68 µl. By generating a controlled and reproducible artificial cough, the simulator allows us to test different ventilation, disinfection, and personal protection scenarios. The system can be used with live pathogens, including influenza virus, which allows isolation precautions used in the healthcare field to be tested without risk of exposure for workers or patients. The information gained from tests with the simulator will help to better understand the transmission of infectious diseases, develop improved techniques for infection control, and improve safety for healthcare workers and patients. PMID:26500387

  7. Cell phone radiation exposure on brain and associated biological systems.

    PubMed

    Kesari, Kavindra Kumar; Siddiqui, Mohd Haris; Meena, Ramovatar; Verma, H N; Kumar, Shivendra

    2013-03-01

    Wireless technologies are ubiquitous today and the mobile phones are one of the prodigious output of this technology. Although the familiarization and dependency of mobile phones is growing at an alarming pace, the biological effects due to the exposure of radiations have become a subject of intense debate. The present evidence on mobile phone radiation exposure is based on scientific research and public policy initiative to give an overview of what is known of biological effects that occur at radiofrequency (RF)/ electromagnetic fields (EMFs) exposure. The conflict in conclusions is mainly because of difficulty in controlling the affecting parameters. Biological effects are dependent not only on the distance and size of the object (with respect to the object) but also on the environmental parameters. Health endpoints reported to be associated with RF include childhood leukemia, brain tumors, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, infertility and some cardiovascular effects. Most of the reports conclude a reasonable suspicion of mobile phone risk that exists based on clear evidence of bio-effects which with prolonged exposures may reasonably be presumed to result in health impacts. The present study summarizes the public issue based on mobile phone radiation exposure and their biological effects. This review concludes that the regular and long term use of microwave devices (mobile phone, microwave oven) at domestic level can have negative impact upon biological system especially on brain. It also suggests that increased reactive oxygen species (ROS) play an important role by enhancing the effect of microwave radiations which may cause neurodegenerative diseases.

  8. Cell phone radiation exposure on brain and associated biological systems.

    PubMed

    Kesari, Kavindra Kumar; Siddiqui, Mohd Haris; Meena, Ramovatar; Verma, H N; Kumar, Shivendra

    2013-03-01

    Wireless technologies are ubiquitous today and the mobile phones are one of the prodigious output of this technology. Although the familiarization and dependency of mobile phones is growing at an alarming pace, the biological effects due to the exposure of radiations have become a subject of intense debate. The present evidence on mobile phone radiation exposure is based on scientific research and public policy initiative to give an overview of what is known of biological effects that occur at radiofrequency (RF)/ electromagnetic fields (EMFs) exposure. The conflict in conclusions is mainly because of difficulty in controlling the affecting parameters. Biological effects are dependent not only on the distance and size of the object (with respect to the object) but also on the environmental parameters. Health endpoints reported to be associated with RF include childhood leukemia, brain tumors, genotoxic effects, neurological effects and neurodegenerative diseases, immune system deregulation, allergic and inflammatory responses, infertility and some cardiovascular effects. Most of the reports conclude a reasonable suspicion of mobile phone risk that exists based on clear evidence of bio-effects which with prolonged exposures may reasonably be presumed to result in health impacts. The present study summarizes the public issue based on mobile phone radiation exposure and their biological effects. This review concludes that the regular and long term use of microwave devices (mobile phone, microwave oven) at domestic level can have negative impact upon biological system especially on brain. It also suggests that increased reactive oxygen species (ROS) play an important role by enhancing the effect of microwave radiations which may cause neurodegenerative diseases. PMID:23678539

  9. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols

    NASA Technical Reports Server (NTRS)

    Carter, Arlen F.; Allen, Robert J.; Mayo, M. Neale; Butler, Carolyn F.; Grossman, Benoist E.; Ismail, Syed; Grant, William B.; Browell, Edward V.; Higdon, Noah S.; Mayor, Shane D.; Ponsardin, Patrick; Hueser, Alene W.

    1994-01-01

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H2O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and greater than 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H2O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H2O absorption-line parameters were performed to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H2O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H2O radiosondes. The H2O distributions measured with the DIAL system differed by less than 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  10. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ≤ 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions.

  11. The Adaptive Aerosol Delivery System in a Telehealth Setting: Patient Acceptance, Performance and Feasibility

    PubMed Central

    Denyer, John; Dodd, Mary; Dyche, Tony; Webb, Kevin; Weller, Peter; Stableforth, David

    2010-01-01

    Abstract Background The telehealth service is one of the fastest growing healthcare segments. It is increasingly utilizing computer technology and telecommunication equipment to either provide continuous vital sign monitoring or facilitate patient care at home, rather than relying solely on in-person care. Methods We conducted a 6-week open study in nineteen patients with cystic fibrosis enrolled from three centers, to investigate patient perception of a telehealth enabled nebulizer system (Prodose Adaptive Aerosol Delivery [AAD] System), which enabled the doorstep delivery of repeat medication. Results The results showed that patient confidence in the device and perception of ease of use was high with no significant change between the start and end of the trial. Views on the home delivery of medication were split between ‘great’ and ‘inconvenient.’ However, if the delivery system had been more flexible and delivered all the patients' drugs, the majority of patients would have had their medication delivered in this way. Conclusions The trial showed that it was possible to build telehealth technology into an advanced nebulizer system, and that patient acceptance of the technology was unlikely to be a barrier to the adoption of such a telehealth system. PMID:20373906

  12. Airborne differential absorption lidar system for measurements of atmospheric water vapor and aerosols.

    PubMed

    Higdon, N S; Browell, E V; Ponsardin, P; Grossmann, B E; Butler, C F; Chyba, T H; Mayo, M N; Allen, R J; Heuser, A W; Grant, W B; Ismail, S; Mayor, S D; Carter, A F

    1994-09-20

    An airborne differential absorption lidar (DIAL) system has been developed at the NASA Langley Research Center for remote measurements of atmospheric water vapor (H(2)O) and aerosols. A solid-state alexandrite laser with a 1-pm linewidth and > 99.85% spectral purity was used as the on-line transmitter. Solid-state avalanche photodiode detector technology has replaced photomultiplier tubes in the receiver system, providing an average increase by a factor of 1.5-2.5 in the signal-to-noise ratio of the H(2)O measurement. By incorporating advanced diagnostic and data-acquisition instrumentation into other subsystems, we achieved additional improvements in system operational reliability and measurement accuracy. Laboratory spectroscopic measurements of H(2)O absorption-line parameters were perfo med to reduce the uncertainties in our knowledge of the absorption cross sections. Line-center H(2)O absorption cross sections were determined, with errors of 3-6%, for more than 120 lines in the 720-nm region. Flight tests of the system were conducted during 1989-1991 on the NASA Wallops Flight Facility Electra aircraft, and extensive intercomparison measurements were performed with dew-point hygrometers and H(2)O radiosondes. The H(2)O distributions measured with the DIAL system differed by ≤ 10% from the profiles determined with the in situ probes in a variety of atmospheric conditions. PMID:20941181

  13. Low level exposure to chemicals and immune system

    SciTech Connect

    Colosio, C. . E-mail: claudio.colosio@icps.it; Birindelli, S.; Corsini, E.; Galli, C.L.; Maroni, M.

    2005-09-01

    Industrialized countries are facing an increase of diseases attributable to an alteration of the immune system function, and concern is growing that this trend could be at least partially attributable to new and modified patterns of exposure to chemicals. Among chemicals matter of concern, pesticides can be included. The Authors have reviewed the existing evidence of pesticide immunotoxicity in humans, showing that existing data are inadequate to raise conclusions on the immunotoxic risk related to these compounds. The limits of existing studies are: poor knowledge on exposure levels, heterogeneity of the approach, and difficulty in giving a prognostic significance to the slight changes often observed. To overcome these limits, the Authors have proposed a tier approach, based on three steps: the first, addressed at pointing out a possible immunomodulation; the second, at refining the results and the third one, when needed, to finalize the study and to point out concordance with previous results. Studies should preferably be carried out through comparison of pre- and post-exposure findings in the same groups of subjects to be examined immediately after the end of the exposure. A simplification of the first step approach can be used by the occupational health physician and the occupational toxicologist. Conclusions on the prognostic significance of the slight changes often observed will be reached only by validating the hypothesis generated by field studies with an epidemiological approach. In this field, the most useful option is represented by longitudinal perspective studies.

  14. DEVELOPMENT OF AN RH -DENUDED MIE ACTIVE SAMPLING SYSTEM AND TARGETED AEROSOL CALIBRATION

    EPA Science Inventory

    The MIE pDR 1200 nephelometer provides time resolved aerosol concentrations during personal and fixed-site sampling. Active (pumped) operation allows defining an upper PM2.5 particle size, however, this dramatically increases the aerosol mass passing through the phot...

  15. Evaluations of Thin Cirrus Contamination and Screening in Ground Aerosol Observations Using Collocated Lidar Systems

    NASA Technical Reports Server (NTRS)

    Huang, Jingfeng; Hsu, N. Christina; Tsay, Si-Chee; Holben, Brent N.; Welton, Ellsworth J.; Smirnov, Alexander; Jeong, Myeong-Jae; Hansell, Richard A.; Berkoff, Timothy A.

    2012-01-01

    Cirrus clouds, particularly sub visual high thin cirrus with low optical thickness, are difficult to be screened in operational aerosol retrieval algorithms. Collocated aerosol and cirrus observations from ground measurements, such as the Aerosol Robotic Network (AERONET) and the Micro-Pulse Lidar Network (MPLNET), provide us with an unprecedented opportunity to examine the susceptibility of operational aerosol products to thin cirrus contamination. Quality assured aerosol optical thickness (AOT) measurements were also tested against the CALIPSO vertical feature mask (VFM) and the MODIS-derived thin cirrus screening parameters for the purpose of evaluating thin cirrus contamination. Key results of this study include: (1) Quantitative evaluations of data uncertainties in AERONET AOT retrievals are conducted. Although AERONET cirrus screening schemes are successful in removing most cirrus contamination, strong residuals displaying strong spatial and seasonal variability still exist, particularly over thin cirrus prevalent regions during cirrus peak seasons, (2) Challenges in matching up different data for analysis are highlighted and corresponding solutions proposed, and (3) Estimation of the relative contributions from cirrus contamination to aerosol retrievals are discussed. The results are valuable for better understanding and further improving ground aerosol measurements that are critical for aerosol-related climate research.

  16. Simulation test of aerosol generation from vessels in the pre-treatment system of fuel reprocessing

    SciTech Connect

    Fujine, Sachio; Kitamura, Koichiro; Kihara, Takehiro

    1997-08-01

    Aerosol concentration and droplet size are measured in off-gas of vessel under various conditions by changing off-gas flow rate, stirring air flow rate, salts concentration and temperature of nitrate solution. Aerosols are also measured under evaporation and air-lift operation. 4 refs., 6 figs.

  17. MODELING THE FORMATION OF SECONDARY ORGANIC AEROSOL WITHIN A COMPREHENSIVE AIR QUALITY MODEL SYSTEM

    EPA Science Inventory

    The aerosol component of the CMAQ model is designed to be an efficient and economical depiction of aerosol dynamics in the atmosphere. The approach taken represents the particle size distribution as the superposition of three lognormal subdistributions, called modes. The proces...

  18. Aerosol generation and distribution system for the Third International Cloud Condensation Nuclei Workshop

    NASA Technical Reports Server (NTRS)

    Katz, U.; Dea, J. Y.

    1981-01-01

    In order to obtain identical samples participating CCN instruments and aerosol characterizing equipment were located along and connected to a 8.2 cm diameter aluminum tube through which the test aerosols were pumped directly from the source at very slight overpressure. Of the total of 29 experiments, 18 were carried out with artificial NaCl or (NH4)2SO4 aerosols. These were generated from salt solutions by pneumatic atomizers of special design to ensure high constancy of the aerosol output concentration. In three experiments with insoluble CCN (AgI, paraffin wax) the aerosols were generated thermally. In some of the tests, an electrostatic classifier was used for narrowing the particle size distributions.

  19. Application of a global nonhydrostatic model with a stretched-grid system to regional aerosol simulations around Japan

    NASA Astrophysics Data System (ADS)

    Goto, D.; Dai, T.; Satoh, M.; Tomita, H.; Uchida, J.; Misawa, S.; Inoue, T.; Tsuruta, H.; Ueda, K.; Ng, C. F. S.; Takami, A.; Sugimoto, N.; Shimizu, A.; Ohara, T.; Nakajima, T.

    2015-02-01

    An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the global and target domains are simulated with a single model, which includes fine meshes covering the target region to calculate meso-scale circulations. The stretched global model involves lower computational costs to simulate atmospheric aerosols with fine horizontal resolutions compared with a global uniform nonhydrostatic model, whereas it may require higher computational costs compared with the general regional models, because the stretched-grid system calculates inside and outside the target domain. As opposed to general regional models, the stretched-grid system requires neither a nesting technique nor lateral boundary conditions. In this study, we developed a new-type regional model for the simulation of aerosols over Japan, especially in the Kanto areas surrounding Tokyo, with a maximum horizontal resolution of approximately 10 km. This model usually reproduces temporal variations and their averages of the observed weather around Japan. This model generally reproduces monthly mean distributions of the observed sulfate and SO2 over East Asia, with high correlations (R > 0.6), but the underestimation of the simulated concentrations by 40% (sulfate) and 50% (SO2). Their underestimation of the simulated sulfate and SO2 concentrations over East Asia are strongly affected by their underestimation in China and possibly by the uncertainty of the simulated precipitation around Japan. In the Kanto area, this model succeeds in simulating the wind patterns and the diurnal transitions around the center of the Kanto area, although it is inadequate to simulate the wind patterns and the diurnal transitions at some sites located at the edge of the Kanto area and surrounded on three sides by mountains, e.g., Maebashi, mainly due to the insufficient horizontal resolution. This model also generally reproduces both diurnal and synoptic variations of the observed

  20. Effects of ammonium sulfate aerosol exposure on lung structure of normal and elastase-impaired rats and guinea pigs

    SciTech Connect

    Busch, R.H.; Buschbom, R.L.; Cannon, W.C.; Lauhala, K.E.; Miller, F.J.; Graham, J.A.; Smith, L.G.

    1984-04-01

    Rats and guinea pigs, pretreated with intratracheally administered elastase or saline, were exposed to 1.03 mg/m/sup 3/ (NH/sub 4/)/sub 2/SO/sub 4/; MMAD, 0.42 ..mu..m. Identically treated controls were sham exposed. Measurements and evaluation of structural changes were conducted using morphometric techniques on SEM photographs and by applying subjective ratings. Pathology studies were conducted by light and electron microscopy. All examination methods confirmed elastase-induced emphysema, which was aggravated by (NH/sub 4/)/sub 2/SO/sub 4/ exposure in the rat. Ammonium sulfate exposure of saline-treated animals produced measurable degrees of enlargement of alveoli, and alveolar ducts and sacs. Electron microscopy revealed increased interstitial collagen in affected lung areas of elastase-treated, (NH/sub 4/)/sub 2/SO/sub 4/-exposed animals. Alveolar-pore size was significantly increased in elastase-treated animals (control and exposed) but not in saline-treated, exposed animals. The data suggest a possible difference between elastase and (NH/sub 4/)/sub 2/SO/sub 4/ in the mechanisms responsible for the increased diameter of alveolar structures. Hypertrophy and hyperplasia of nonciliated epithelial cells of the small airways and of the Type II alveolar cells were observed in otherwise untreated guinea pigs exposed to (NH/sub 4/)/sub 2/SO/sub 4/ but not in elastase-treated guinea pigs, nor in any of the rats. 12 references.

  1. Design considerations for ozone and acid aerosol exposure and health investigations: the Fairview Lake summer camp - photochemical smog case study

    SciTech Connect

    Lioy, P.J.; Spektor, D.; Thurston, G.; Citak, K.; Lippmann, M.; Bock, N.; Speizer, F.E.; Hayes, C.

    1987-01-01

    The health effects associated with ozone and acidic particulate sulfate exposures to active children have been and are being addressed in field epidemiological studies at summer camps in rural areas of the Northeastern US. The rationale and study design for studies, which have been conducted in Pennsylvania and New Jersey, are developed and reviewed. As background, results are summarized for human clinical and epidemiological studies and animal studies. These provided the basis for selection of health outcomes measured results from chemical characterization and transport studies are reviewed to define the criteria used for selection of a site which is effected by high ozone and acid species during photochemical smog episodes. The integration of the study design is discussed in detail by reviewing its application to the 1984 - Fairview Lake Camp Study (July 8 to August 4). The features of the camp study are reviewed, including the study population, pulmonary function procedures and analyses, air pollution monitoring instrumentation, and the site characteristics. The pollution exposure data are presented, for ozone and acidic sulfates and examined for the range and distribution concentration. Further information is provided on the intensity and duration of episodes encountered over the course of the study. Episodes occurred which had ozone and acid sulfates, ozone alone, and acid sulfates alone. 56 references, 9 figures.

  2. Validation of reactive gases and aerosols in the MACC global analysis and forecast system

    NASA Astrophysics Data System (ADS)

    Eskes, H.; Huijnen, V.; Arola, A.; Benedictow, A.; Blechschmidt, A.-M.; Botek, E.; Boucher, O.; Bouarar, I.; Chabrillat, S.; Cuevas, E.; Engelen, R.; Flentje, H.; Gaudel, A.; Griesfeller, J.; Jones, L.; Kapsomenakis, J.; Katragkou, E.; Kinne, S.; Langerock, B.; Razinger, M.; Richter, A.; Schultz, M.; Schulz, M.; Sudarchikova, N.; Thouret, V.; Vrekoussis, M.; Wagner, A.; Zerefos, C.

    2015-11-01

    The European MACC (Monitoring Atmospheric Composition and Climate) project is preparing the operational Copernicus Atmosphere Monitoring Service (CAMS), one of the services of the European Copernicus Programme on Earth observation and environmental services. MACC uses data assimilation to combine in situ and remote sensing observations with global and regional models of atmospheric reactive gases, aerosols, and greenhouse gases, and is based on the Integrated Forecasting System of the European Centre for Medium-Range Weather Forecasts (ECMWF). The global component of the MACC service has a dedicated validation activity to document the quality of the atmospheric composition products. In this paper we discuss the approach to validation that has been developed over the past 3 years. Topics discussed are the validation requirements, the operational aspects, the measurement data sets used, the structure of the validation reports, the models and assimilation systems validated, the procedure to introduce new upgrades, and the scoring methods. One specific target of the MACC system concerns forecasting special events with high-pollution concentrations. Such events receive extra attention in the validation process. Finally, a summary is provided of the results from the validation of the latest set of daily global analysis and forecast products from the MACC system reported in November 2014.

  3. Measurements of the Vertical Structure of Aerosols and Clouds Over the Ocean Using Micro-Pulse LIDAR Systems

    NASA Technical Reports Server (NTRS)

    Welton, Ellsworth J.; Spinhirne, James D.; Campbell, James R.; Berkoff, Timothy A.; Bates, David; Starr, David OC. (Technical Monitor)

    2001-01-01

    The determination of the vertical distribution of aerosols and clouds over the ocean is needed for accurate retrievals of ocean color from satellites observations. The presence of absorbing aerosol layers, especially at altitudes above the boundary layer, has been shown to influence the calculation of ocean color. Also, satellite data must be correctly screened for the presence of clouds, particularly cirrus, in order to measure ocean color. One instrument capable of providing this information is a lidar, which uses pulses of laser light to profile the vertical distribution of aerosol and cloud layers in the atmosphere. However, lidar systems prior to the 1990s were large, expensive, and not eye-safe which made them unsuitable for cruise deployments. During the 1990s the first small, autonomous, and eye-safe lidar system became available: the micro-pulse lidar, or MPL. The MPL is a compact and eye-safe lidar system capable of determining the range of aerosols and clouds by firing a short pulse of laser light (523 nm) and measuring the time-of-flight from pulse transmission to reception of a returned signal. The returned signal is a function of time, converted into range using the speed of light, and is proportional to the amount of light backscattered by atmospheric molecules (Rayleigh scattering), aerosols, and clouds. The MPL achieves ANSI eye-safe standards by sending laser pulses at low energy (micro-J) and expanding the beam to 20.32 cm in diameter. A fast pulse-repetition-frequency (2500 Hz) is used to achieve a good signal-to-noise, despite the low output energy. The MPL has a small field-of-view (< 100 micro-rad) and signals received with the instrument do not contain multiple scattering effects. The MPL has been used successfully at a number of long-term sites and also in several field experiments around the world.

  4. Deployable Plume and Aerosol Release Prediction and Tracking System. Nuclear Non-Proliferation Task 1. Final Report

    SciTech Connect

    Kleppe, John; Norris, William; Etezadi, Mehdi

    2006-07-19

    This contract was awarded in response to a proposal in which a deployable plume and aerosol release prediction and tracking system would be designed, fabricated, and tested. The system would gather real time atmospheric data and input it into a real time atmospheric model that could be used for plume predition and tracking. The system would be able to be quickly deployed by aircraft to points of interest or positioned for deployment by vehicles. The system would provide three dimensional (u, v, and w) wind vector data, inversion height measurements, surface wind information, classical weather station data, and solar radiation. The on-board real time computer model would provide the prediction of the behavior of plumes and released aerosols.

  5. Naval biomedical research laboratory, programmed environment, aerosol facility.

    PubMed

    Goldberg, L J

    1971-02-01

    Mathematical considerations of the behavior of aerosolized particles in a rotating drum are presented, and the rotating drum as an aerosol-holding device is compared with a stirred settling chamber. The basic overall design elements of a facility employing eight rotating drums are presented. This facility provides an environment in which temperature can be maintained within 0.5 F (0.25 C) of any set point over a range of 50 to 120 F (10 to 49 C); concomitantly the relative humidity within any selected drum may be controlled in a nominal range of 0 to 90%. Some of the major technical aspects of operating this facility are also presented, including handling of air support systems, aerosol production, animal exposure, aerosol monitoring, and sampling. PMID:5549701

  6. Naval Biomedical Research Laboratory, Programmed Environment, Aerosol Facility

    PubMed Central

    Goldberg, L. J.

    1971-01-01

    Mathematical considerations of the behavior of aerosolized particles in a rotating drum are presented, and the rotating drum as an aerosol-holding device is compared with a stirred settling chamber. The basic overall design elements of a facility employing eight rotating drums are presented. This facility provides an environment in which temperature can be maintained within 0.5 F (0.25 C) of any set point over a range of 50 to 120 F (10 to 49 C); concomitantly the relative humidity within any selected drum may be controlled in a nominal range of 0 to 90%. Some of the major technical aspects of operating this facility are also presented, including handling of air support systems, aerosol production, animal exposure, aerosol monitoring, and sampling. Images PMID:5549701

  7. Respiratory effects of occupational exposure to an epoxy resin system.

    PubMed

    Sargent, E V; Brubaker, R E; Mitchell, C A

    1976-01-01

    A standardized respiratory questionnaire and pulmonary function tests were used to examine thirty-four employees of a snow-ski manufacturing plant, including twenty-five workers who were exposed to an epoxy resin system containing the amine hardener 3-dimethylamino propylamine (3-DMAPA). Maximum expiratory flow-volume curves were obtained on Monday and Thursday, before and after each shift, and FVC, FEV1.0, MEF50%, and MEF25% were caculated. Environmental measurements of the total amine levels were found to range from 0.41 to 1.38 ppm. The group with the greatest exposure (0.55-1.38 ppm) showed significant decreases in lung function over Monday and over the week. Although all employees in this group showed decreases in pulmonary function, acute changes were greater in present cigarette smokers and in subjects who reported respiratory symptoms upon exposure to the epoxy resin system. There was no evidence of permanent loss of lung function in subjects with either the highest or longest exposure.

  8. Embryotoxicity study of monomeric 4,4'-methylenediphenyl diisocyanate (MDI) aerosol after inhalation exposure in Wistar rats.

    PubMed

    Buschmann, J; Koch, W; Fuhst, R; Heinrich, U

    1996-07-01

    One of the uses of MDI is as an alternative to formaldehyde in the manufacture of furniture, its main route of exposure to humans being by inhalation. There have been no previous studies on the potential prenatal toxic effects of this compound. To close this gap in information, gravid Wistar rats, Crl:(WI)BR, were exposed by whole-body inhalation to clean air (control) and to 1, 3, and 9 mg/m3 MDI, respectively, for 6 hr per day from Days 6 to 15 post conception (p.c.). Rats were killed on Day 20 p.c. and the following results were obtained: Treatment caused a dose-dependent decrease in food consumption in all substance-treated groups during exposure, returning to normal values after cessation of treatment. The lung weights in the high-dose group were significantly increased compared to the sham-treated control animals. Treatment did not influence any other material and/or fetal parameters investigated (maternal weight gain, number of corpora lutea, implantation sites, pre- and postimplantation loss, fetal and placental weights, gross and visceral anomalies, degree of ossification), although a slight but significant increase in litters with fetuses displaying asymmetric sternebra(e) was observed after treatment with the highest dose of 9 mg/m3. Although the relevance of an increase of this minor anomaly in doses which cause toxic effects in dams (reduced food consumption, increased lung weights) is limited and the number observed is within the limits of biological variability, a substance-induced effect in the high-dose group cannot be excluded with certainty. Consequently, a no embryotoxic effect level of 3 mg/m3 was determined. PMID:8812241

  9. Organic Carbon and Light Absorption Analysis of Los Angeles Aerosols through an Online Sampling System

    NASA Astrophysics Data System (ADS)

    Hartley, M. K.; Hawkins, L. N.

    2013-12-01

    Brown carbon is a comprehensive term for organic compounds with wavelength dependent light absorption. Common sources of brown carbon include fossil fuel combustion, biomass burning and aqueous reactions in cloud and fog water. Nitrophenols have been proposed as one source of brown carbon in the Los Angeles area. In this work, we are interested in the relative strengths of each of these sources within Los Angeles. We have implemented a continuous online system of collection and analysis within our lab. The system consists of a particle into liquid sampler (PILS), a liquid waveguide capillary cell (LWCC) and a total organic carbon analyzer (TOC). Online analysis of organic carbon content and UV-Vis absorption has allowed us to study the ratio of the two as an intrinsic property of the aerosol particles, called the 'absorption coefficient.' Using a rearrangement of Beer's Law, we have analyzed the relationship: ɛ = A / C (where ɛ is the absorption coefficient, A is the light absorption of the sample and C is the concentration of organic carbon in the sample). Using our continuous online system, we have collected absorption spectra and total organic carbon measurements over several weeks and in varying environmental conditions. Our work has shown that different weather conditions, along with fog or cloud formation, can affect the absorption coefficient of the brown carbon compounds in the air.

  10. Prenatal triclosan exposure and cord blood immune system biomarkers.

    PubMed

    Ashley-Martin, Jillian; Dodds, Linda; Arbuckle, Tye E; Marshall, Jean

    2016-07-01

    Triclosan is widely used as an antimicrobial agent and preservative that has been hypothesized to play a role in asthma and allergic disease. The limited body of literature regarding the allergenicity of triclosan has not evaluated prenatal exposure and subsequent potential effects on the developing immune system. The objective of the present study was to determine the association between prenatal urinary triclosan concentrations and cord blood immune system biomarker concentrations. Umbilical cord blood samples were obtained from the Maternal-Infant Research on Environmental Chemicals (MIREC) Biobank and were tested for three immune system biomarkers: immunoglobulin E (IgE), thymic stromal lymphopoietin (TSLP), and interleukin-33 (IL-33). Triclosan concentrations were measured in urine at 6-13 weeks gestation. No statistically significant associations were observed between prenatal triclosan concentrations and elevated concentrations of any immune system biomarker (n=1219 participants). Longitudinal studies are necessary to determine how the observed findings at birth translate into childhood.

  11. An inexpensive fathead minnow egg incubation and toxicant exposure system

    SciTech Connect

    Diamond, S.A.; Oris, J.T.; Guttman, S.I.

    1995-08-01

    Several methods have been developed for bulk hatching of fathead minnow eggs for laboratory and commercial culture. These methods generally involve placing whole, egg-laden breeding substrates in an aeration or water-flow device, or manually removing eggs from breeding substrates. Eggs removed from substrates are then hatched in Downing or McDonald jar hatching devices or are agitated in cylindrical vessels from which larvae are manually removed. These methods are difficult to incorporate into toxicity tests involving determination of hatching success in replicate systems. Both require either continuous water flow to individual hatching chambers or frequent static renewal, which adds to the labor of separating larvae from unhatched eggs. The authors report on an inexpensive, easily constructed system for hatching fathead minnow eggs and maintaining hatched larvae for growth and survivorship studies. Data are presented to illustrate the use of the system for toxicant exposures. This system has applications for both field and laboratory studies.

  12. Organic aerosols

    SciTech Connect

    Penner, J.E.

    1994-01-01

    Organic aerosols scatter solar radiation. They may also either enhance or decrease concentrations of cloud condensation nuclei. This paper summarizes observed concentrations of aerosols in remote continental and marine locations and provides estimates for the sources of organic aerosol matter. The anthropogenic sources of organic aerosols may be as large as the anthropogenic sources of sulfate aerosols, implying a similar magnitude of direct forcing of climate. The source estimates are highly uncertain and subject to revision in the future. A slow secondary source of organic aerosols of unknown origin may contribute to the observed oceanic concentrations. The role of organic aerosols acting as cloud condensation nuclei (CCN) is described and it is concluded that they may either enhance or decrease the ability of anthropogenic sulfate aerosols to act as CCN.

  13. Responding to detection of aerosolized Bacillus anthracis by autonomous detection systems in the workplace.

    PubMed

    Meehan, Patrick J; Rosenstein, Nancy E; Gillen, Matthew; Meyer, Richard F; Kiefer, Max J; Deitchman, Scott; Besser, Richard E; Ehrenberg, Richard L; Edwards, Kathleen M; Martinez, Kenneth F

    2004-06-01

    Autonomous detection systems (ADSs) are under development to detect agents of biologic and chemical terror in the environment. These systems will eventually be able to detect biologic and chemical hazards reliably and provide approximate real-time alerts that an agent is present. One type of ADS that tests specifically for Bacillus anthracis is being deployed in hundreds of postal distribution centers across the United States. Identification of aerosolized B. anthracis spores in an air sample can facilitate prompt on-site decontamination of workers and subsequent administration of postexposure prophylaxis to prevent inhalational anthrax. Every employer who deploys an ADS should develop detailed plans for responding to a positive signal. Responding to ADS detection of B. anthracis involves coordinating responses with community partners and should include drills and exercises with these partners. This report provides guidelines in the following six areas: 1) response and consequence management planning, including the minimum components of a facility response plan; 2) immediate response and evacuation; 3) decontamination of potentially exposed workers to remove spores from clothing and skin and prevent introduction of B. anthracis into the worker's home and conveyances; 4) laboratory confirmation of an ADS signal; 5) steps for evaluating potentially contaminated environments; and 6) postexposure prophylaxis and follow-up. PMID:15179360

  14. Aerosolized antibiotics for ventilator-associated pneumonia: lessons from experimental studies.

    PubMed

    Rouby, Jean-Jacques; Bouhemad, Belaïd; Monsel, Antoine; Brisson, Hélène; Arbelot, Charlotte; Lu, Qin

    2012-12-01

    The aim of this review is to perform a critical analysis of experimental studies on aerosolized antibiotics and draw lessons for clinical use in patients with ventilator-associated pneumonia. Ultrasonic or vibrating plate nebulizers should be preferred to jet nebulizers. During the nebulization period, specific ventilator settings aimed at decreasing flow turbulence should be used, and discoordination with the ventilator should be avoided. The appropriate dose of aerosolized antibiotic can be determined as the intravenous dose plus extrapulmonary deposition. If these conditions are strictly respected, then high lung tissue deposition associated with rapid and efficient bacterial killing can be expected. For aerosolized aminoglycosides and cephalosporins, a decrease in systemic exposure leading to reduced toxicity is not proven by experimental studies. Aerosolized colistin, however, does not easily cross the alveolar-capillary membrane even in the presence of severe lung infection, and high doses can be delivered by nebulization without significant systemic exposure. PMID:23135264

  15. An 8-Month Systems Toxicology Inhalation/Cessation Study in Apoe-/- Mice to Investigate Cardiovascular and Respiratory Exposure Effects of a Candidate Modified Risk Tobacco Product, THS 2.2, Compared With Conventional Cigarettes.

    PubMed

    Phillips, Blaine; Veljkovic, Emilija; Boué, Stéphanie; Schlage, Walter K; Vuillaume, Gregory; Martin, Florian; Titz, Bjoern; Leroy, Patrice; Buettner, Ansgar; Elamin, Ashraf; Oviedo, Alberto; Cabanski, Maciej; De León, Héctor; Guedj, Emmanuel; Schneider, Thomas; Talikka, Marja; Ivanov, Nikolai V; Vanscheeuwijck, Patrick; Peitsch, Manuel C; Hoeng, Julia

    2016-02-01

    Smoking cigarettes is a major risk factor in the development and progression of cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). Modified risk tobacco products (MRTPs) are being developed to reduce smoking-related health risks. The goal of this study was to investigate hallmarks of COPD and CVD over an 8-month period in apolipoprotein E-deficient mice exposed to conventional cigarette smoke (CS) or to the aerosol of a candidate MRTP, tobacco heating system (THS) 2.2. In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS exposure was assessed. Engaging a systems toxicology approach, exposure effects were investigated using physiology and histology combined with transcriptomics, lipidomics, and proteomics. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function and alveolar damage). Atherogenic effects of CS exposure included altered lipid profiles and aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS, 29.9 mg/m(3)) neither induced lung inflammation or emphysema nor did it consistently change the lipid profile or enhance the plaque area. Cessation or switching to THS2.2 reversed the inflammatory responses and halted progression of initial emphysematous changes and the aortic plaque area. Biological processes, including senescence, inflammation, and proliferation, were significantly impacted by CS but not by THS2.2 aerosol. Both, cessation and switching to THS2.2 reduced these perturbations to almost sham exposure levels. In conclusion, in this mouse model cessation or switching to THS2.2 retarded the progression of CS-induced atherosclerotic and emphysematous changes, while THS2.2 aerosol alone had minimal adverse effects.

  16. An 8-Month Systems Toxicology Inhalation/Cessation Study in Apoe-/- Mice to Investigate Cardiovascular and Respiratory Exposure Effects of a Candidate Modified Risk Tobacco Product, THS 2.2, Compared With Conventional Cigarettes.

    PubMed

    Phillips, Blaine; Veljkovic, Emilija; Boué, Stéphanie; Schlage, Walter K; Vuillaume, Gregory; Martin, Florian; Titz, Bjoern; Leroy, Patrice; Buettner, Ansgar; Elamin, Ashraf; Oviedo, Alberto; Cabanski, Maciej; De León, Héctor; Guedj, Emmanuel; Schneider, Thomas; Talikka, Marja; Ivanov, Nikolai V; Vanscheeuwijck, Patrick; Peitsch, Manuel C; Hoeng, Julia

    2016-02-01

    Smoking cigarettes is a major risk factor in the development and progression of cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). Modified risk tobacco products (MRTPs) are being developed to reduce smoking-related health risks. The goal of this study was to investigate hallmarks of COPD and CVD over an 8-month period in apolipoprotein E-deficient mice exposed to conventional cigarette smoke (CS) or to the aerosol of a candidate MRTP, tobacco heating system (THS) 2.2. In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS exposure was assessed. Engaging a systems toxicology approach, exposure effects were investigated using physiology and histology combined with transcriptomics, lipidomics, and proteomics. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function and alveolar damage). Atherogenic effects of CS exposure included altered lipid profiles and aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS, 29.9 mg/m(3)) neither induced lung inflammation or emphysema nor did it consistently change the lipid profile or enhance the plaque area. Cessation or switching to THS2.2 reversed the inflammatory responses and halted progression of initial emphysematous changes and the aortic plaque area. Biological processes, including senescence, inflammation, and proliferation, were significantly impacted by CS but not by THS2.2 aerosol. Both, cessation and switching to THS2.2 reduced these perturbations to almost sham exposure levels. In conclusion, in this mouse model cessation or switching to THS2.2 retarded the progression of CS-induced atherosclerotic and emphysematous changes, while THS2.2 aerosol alone had minimal adverse effects. PMID:26609137

  17. An 8-Month Systems Toxicology Inhalation/Cessation Study in Apoe−/− Mice to Investigate Cardiovascular and Respiratory Exposure Effects of a Candidate Modified Risk Tobacco Product, THS 2.2, Compared With Conventional Cigarettes

    PubMed Central

    Phillips, Blaine; Veljkovic, Emilija; Boué, Stéphanie; Schlage, Walter K.; Vuillaume, Gregory; Martin, Florian; Titz, Bjoern; Leroy, Patrice; Buettner, Ansgar; Elamin, Ashraf; Oviedo, Alberto; Cabanski, Maciej; De León, Héctor; Guedj, Emmanuel; Schneider, Thomas; Talikka, Marja; Ivanov, Nikolai V.; Vanscheeuwijck, Patrick; Peitsch, Manuel C.; Hoeng, Julia

    2016-01-01

    Smoking cigarettes is a major risk factor in the development and progression of cardiovascular disease (CVD) and chronic obstructive pulmonary disease (COPD). Modified risk tobacco products (MRTPs) are being developed to reduce smoking-related health risks. The goal of this study was to investigate hallmarks of COPD and CVD over an 8-month period in apolipoprotein E-deficient mice exposed to conventional cigarette smoke (CS) or to the aerosol of a candidate MRTP, tobacco heating system (THS) 2.2. In addition to chronic exposure, cessation or switching to THS2.2 after 2 months of CS exposure was assessed. Engaging a systems toxicology approach, exposure effects were investigated using physiology and histology combined with transcriptomics, lipidomics, and proteomics. CS induced nasal epithelial hyperplasia and metaplasia, lung inflammation, and emphysematous changes (impaired pulmonary function and alveolar damage). Atherogenic effects of CS exposure included altered lipid profiles and aortic plaque formation. Exposure to THS2.2 aerosol (nicotine concentration matched to CS, 29.9 mg/m3) neither induced lung inflammation or emphysema nor did it consistently change the lipid profile or enhance the plaque area. Cessation or switching to THS2.2 reversed the inflammatory responses and halted progression of initial emphysematous changes and the aortic plaque area. Biological processes, including senescence, inflammation, and proliferation, were significantly impacted by CS but not by THS2.2 aerosol. Both, cessation and switching to THS2.2 reduced these perturbations to almost sham exposure levels. In conclusion, in this mouse model cessation or switching to THS2.2 retarded the progression of CS-induced atherosclerotic and emphysematous changes, while THS2.2 aerosol alone had minimal adverse effects. PMID:26609137

  18. NASA GES DISC Level 2 Aerosol Analysis and Visualization Services

    NASA Technical Reports Server (NTRS)

    Wei, Jennifer; Petrenko, Maksym; Ichoku, Charles; Yang, Wenli; Johnson, James; Zhao, Peisheng; Kempler, Steve

    2015-01-01

    Overview of NASA GES DISC Level 2 aerosol analysis and visualization services: DQViz (Data Quality Visualization)MAPSS (Multi-sensor Aerosol Products Sampling System), and MAPSS_Explorer (Multi-sensor Aerosol Products Sampling System Explorer).

  19. Impact of Aerosols and Atmospheric Thermodynamics on Cloud Properties within the Climate System

    NASA Technical Reports Server (NTRS)

    Matsui, Toshihisa; Masunaga, Hirohiko; Pielke, Roger, Sr.; Tao, Wei-Kuo

    2003-01-01

    A combination of cloud-top and columnar droplet sizes derived from the multi Tropical Rainfall Measurement Mission (TRMM) sensors reveals the sensitivity of the aerosols effect on cloud-precipitation process due to environmental vertical thermodynamic structure. First, the magnitude of aerosol indirect effect could be larger with the analysis of columnar droplet sizes than that derived from the cloud-top droplet sizes, since column-droplet size can account for the broader droplet spectra in the cloud layers. Second, a combination of cloud- top and columnar droplet sizes reveals that the warm rain process is prevented regardless of the aerosols concentration under a high static stability such as when a strong temperature inversion exists, while a high aerosol concentration suppresses the warm rain formulation under a low static stability.

  20. Sensitivity studies using Regional Atmospheric Modeling System to analyze the impact of dust and aerosol on precipitation in the Colorado River Basin

    NASA Astrophysics Data System (ADS)

    Jha, V.; Cotton, W. R.; Carrio, G. G.; Pierce, J. R.

    2015-12-01

    A modeling study is performed in the Colorado River Basin by varying the ratio of dust and aerosol pollution. The Colorado State University Regional Atmospheric Modeling system (RAMS) version 6.0 is used for the analyses with the aerosol and dust pollution data being nudged from the GEOS-Chem. RAMS was modified to ingest GEOS-CHEM output data and periodically update aerosol fields. GEOS-CHEM is a chemical transport model which uses assimilated meteorological data from the NASA Goddard Earth Observation System (GEOS). The aerosol data comprise a sum of hydrophobic and hydrophilic black carbon and organic aerosol, hydrophilic SOAs, hydrocarbon oxidation and inorganic aerosols (nitrate, sulfate and ammonium). In addition, a RAMS-based dust source and transport model is used. The sensitivity studies are 5 different kinds. The base study has both the dust and aerosol pollution data ON. The Case 2 has dust OFF with only the aerosol sources ON. The Case 3 has the aerosol sources ON with dust multiplied by a factor of 3. Case 4 has the aerosol sources ON with dust multiplied by a factor of 10. Case 5 and Case 6 are the simulations where dust can act only as CCN and only as IN respectively. It was found that the precipitation increases when dust is increased 3 times. However, the response is non-monotonic when dust is increased 10 times and the response depends on the environmental conditions. Dust acting as CCN acts in opposition to dust acting as IN. In general, dust acting as IN tends to enhance precipitation in wintertime orographic clouds.

  1. Radiative effects of African dust and smoke observed from Clouds and the Earth's Radiant Energy System (CERES) and Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) data

    NASA Astrophysics Data System (ADS)

    Yorks, John E.; McGill, Matt; Rodier, Sharon; Vaughan, Mark; Hu, Yongxiang; Hlavka, Dennis

    2009-09-01

    Cloud and aerosol effects have a significant impact on the atmospheric radiation budget in the tropical Atlantic because of the spatial and temporal extent of desert dust and smoke from biomass burning in the atmosphere. The influences of African dust and smoke aerosols on cloud radiative properties over the tropical Atlantic Ocean were analyzed for the month of July for 3 years (2006-2008) using colocated data collected by the Cloud-Aerosol Lidar with Orthogonal Polarization (CALIOP) and Clouds and the Earth's Radiant Energy System (CERES) instruments on the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) and Aqua satellites. Aerosol layer height and type can be accurately determined using CALIOP data through directly measured parameters such as optical depth, volume depolarization ratio, attenuated backscatter, and color ratio. On average, clouds below 5 km had a daytime instantaneous shortwave (SW) radiative flux of 270.2 ± 16.9 W/m2 and thin cirrus clouds had a SW radiative flux of 208.0 ± 12.7 W/m2. When dust aerosols interacted with clouds below 5 km, as determined from CALIPSO, the SW radiative flux decreased to 205.4 ± 13.0 W/m2. Similarly, smoke aerosols decreased the SW radiative flux of low clouds to a value of 240.0 ± 16.6 W/m2. These decreases in SW radiative flux were likely attributed to the aerosol layer height and changes in cloud microphysics. CALIOP lidar observations, which more accurately identify aerosol layer height than passive instruments, appear essential for better understanding of cloud-aerosol interactions, a major uncertainty in predicting the climate system.

  2. Analysis of Atmospheric Aerosols

    NASA Astrophysics Data System (ADS)

    Prather, Kimberly A.; Hatch, Courtney D.; Grassian, Vicki H.

    2008-07-01

    Aerosols represent an important component of the Earth's atmosphere. Because aerosols are composed of solid and liquid particles of varying chemical complexity, size, and phase, large challenges exist in understanding how they impact climate, health, and the chemistry of the atmosphere. Only through the integration of field, laboratory, and modeling analysis can we begin to unravel the roles atmospheric aerosols play in these global processes. In this article, we provide a brief review of the current state of the science in the analysis of atmospheric aerosols and some important challenges that need to be overcome before they can become fully integrated. It is clear that only when these areas are effectively bridged can we fully understand the impact that atmospheric aerosols have on our environment and the Earth's system at the level of scientific certainty necessary to design and implement sound environmental policies.

  3. A novel exposure system for the efficient and controlled deposition of aerosol particles onto cell cultures.

    PubMed

    Savi, Melanie; Kalberer, Markus; Lang, Doris; Ryser, Manuel; Fierz, Martin; Gaschen, Annina; Ricka, Jaroslav; Geiser, Marianne

    2008-08-01

    Epidemiologic studies have shown correlations between morbidity and particles < or = 2.5 microm generated from pollution processes and manufactured nanoparticles. Thereby nanoparticles seem to play a specific role. The interaction of particles with the lung, the main pathway of undesired particle uptake, is poorly understood. In most studies investigating these interactions in vitro, particle deposition differs greatly from the in vivo situation, causing controversial results. We present a nanoparticle deposition chamber to expose lung cells mimicking closely the particle deposition conditions in the lung. In this new deposition chamber, particles are deposited very efficiently, reproducibly, and uniformly onto the cell culture, a key aspect if cell responses are quantified in respect to the deposited particle number. In situ analyses of the lung cells, e.g., the ciliary beat frequency, indicative of the defense capability of the cells, are complemented by off-line biochemical, physiological, and morphological cell analyses.

  4. Lifting options for stratospheric aerosol geoengineering: advantages of tethered balloon systems.

    PubMed

    Davidson, Peter; Burgoyne, Chris; Hunt, Hugh; Causier, Matt

    2012-09-13

    The Royal Society report 'Geoengineering the Climate' identified solar radiation management using albedo-enhancing aerosols injected into the stratosphere as the most affordable and effective option for geoengineering, but did not consider in any detail the options for delivery. This paper provides outline engineering analyses of the options, both for batch-delivery processes, following up on previous work for artillery shells, missiles, aircraft and free-flying balloons, as well as a more lengthy analysis of continuous-delivery systems that require a pipe connected to the ground and supported at a height of 20 km, either by a tower or by a tethered balloon. Towers are shown not to be practical, but a tethered balloon delivery system, with high-pressure pumping, appears to have much lower operating and capital costs than all other delivery options. Instead of transporting sulphuric acid mist precursors, such a system could also be used to transport slurries of high refractive index particles such as coated titanium dioxide. The use of such particles would allow useful experiments on opacity, coagulation and atmospheric chemistry at modest rates so as not to perturb regional or global climatic conditions, thus reducing scale-up risks. Criteria for particle choice are discussed, including the need to minimize or prevent ozone destruction. The paper estimates the time scales and relatively modest costs required if a tethered balloon system were to be introduced in a measured way with testing and development work proceeding over three decades, rather than in an emergency. The manufacture of a tether capable of sustaining the high tensions and internal pressures needed, as well as strong winds, is a significant challenge, as is the development of the necessary pumping and dispersion technologies. The greatest challenge may be the manufacture and launch of very large balloons, but means have been identified to significantly reduce the size of such balloons or aerostats.

  5. Cleanup worker exposures to hazardous chemicals at a former nuclear weapons plant: piloting of an exposure surveillance system.

    PubMed

    LaMontagne, A D; Van Dyke, M V; Martyny, J W; Ruttenber, A J

    2001-02-01

    Cleanup of former U.S. Department of Energy (DOE) nuclear weapons production facilities involves potential exposures to various hazardous chemicals. We have collaboratively developed and piloted an exposure database and surveillance system for cleanup worker hazardous chemical exposure data with a cleanup contractor at the Rocky Flats Environmental Technology Site (RFETS). A unique system feature is the incorporation of a 34-category work task-coding scheme. This report presents an overview of the data captured by this system during development and piloting from March 1995 through August 1998. All air samples collected were entered into the system. Of the 859 breathing zone samples collected, 103 unique employees and 39 unique compounds were represented. Breathing zone exposure levels were usually low (86% of breathing zone samples were below analytical limits of detection). The use of respirators and other exposure controls was high (87 and 88%, respectively). Occasional high-level excursions did occur. Detailed quantitative summaries are provided for the six most monitored compounds: asbestos, beryllium, carbon tetrachloride, chromium, lead, and methylene chloride. Task and job title data were successfully collected for most samples, and showed specific cleanup activities by pipe fitters to be the most commonly represented in the database. Importantly, these results demonstrate the feasibility of the implementation of integrated exposure database and surveillance systems by practicing industrial hygienists employed in industry as well as the preventive potential and research uses of such systems. This exposure database and surveillance system--the central features of which are applicable in any industrial work setting--has enabled one of the first systematic quantitative characterizations of DOE cleanup worker exposures to hazardous chemicals. PMID:11217724

  6. Cleanup worker exposures to hazardous chemicals at a former nuclear weapons plant: piloting of an exposure surveillance system.

    PubMed

    LaMontagne, A D; Van Dyke, M V; Martyny, J W; Ruttenber, A J

    2001-02-01

    Cleanup of former U.S. Department of Energy (DOE) nuclear weapons production facilities involves potential exposures to various hazardous chemicals. We have collaboratively developed and piloted an exposure database and surveillance system for cleanup worker hazardous chemical exposure data with a cleanup contractor at the Rocky Flats Environmental Technology Site (RFETS). A unique system feature is the incorporation of a 34-category work task-coding scheme. This report presents an overview of the data captured by this system during development and piloting from March 1995 through August 1998. All air samples collected were entered into the system. Of the 859 breathing zone samples collected, 103 unique employees and 39 unique compounds were represented. Breathing zone exposure levels were usually low (86% of breathing zone samples were below analytical limits of detection). The use of respirators and other exposure controls was high (87 and 88%, respectively). Occasional high-level excursions did occur. Detailed quantitative summaries are provided for the six most monitored compounds: asbestos, beryllium, carbon tetrachloride, chromium, lead, and methylene chloride. Task and job title data were successfully collected for most samples, and showed specific cleanup activities by pipe fitters to be the most commonly represented in the database. Importantly, these results demonstrate the feasibility of the implementation of integrated exposure database and surveillance systems by practicing industrial hygienists employed in industry as well as the preventive potential and research uses of such systems. This exposure database and surveillance system--the central features of which are applicable in any industrial work setting--has enabled one of the first systematic quantitative characterizations of DOE cleanup worker exposures to hazardous chemicals.

  7. Large scale in vitro experiment system for 2 GHz exposure.

    PubMed

    Iyama, Takahiro; Ebara, Hidetoshi; Tarusawa, Yoshiaki; Uebayashi, Shinji; Sekijima, Masaru; Nojima, Toshio; Miyakoshi, Junji

    2004-12-01

    A beam formed radiofrequency (RF) exposure-incubator employing a horn antenna, a dielectric lens, and a culture case in an anechoic chamber is developed for large scale in vitro studies. The combination of an open type RF exposure source and a culture case through which RF is transmitted realizes a uniform electric field (+/-1.5 dB) in a 300 x 300 mm area that accommodates 49 35 mm diameter culture dishes. This large culture dish area enables simultaneous RF exposure of a large number of cells or various cell lines. The RF exposure source operates at 2142.5 MHz corresponding to the middle frequency of the downlink band of the International Mobile Telecommunication 2000 (IMT-2000) cellular system. The dielectric lens, which has a gain of 7 dB, focuses RF energy in the direction of the culture case and provides a uniform electric field. The culture case is sealed and connected to the main unit for environmental control, located outside the anechoic chamber, via ducts. The temperature at the center of the tray, which contains the culture dishes in the culture room, is maintained at 37.0 +/- 0.2 degrees C by air circulation. In addition, the appropriate CO2 density and humidity supplied to the culture case realizes stable long-term culture conditions. Specific absorption rate (SAR) dosimetry is performed using an electric field measurement technique and the Finite Difference Time Domain (FDTD) calculation method. The results indicate that the mean SAR of the culture fluid at the bottom of the 49 (7 x 7 array) culture dishes used in the in vitro experiments is 0.175 W/kg for an antenna input power of 1 W and the standard deviation of the SAR distribution is 59%. When only 25 culture dishes (5 x 5 array) are evaluated, the mean SAR is 0.139 W/kg for the same antenna input power and the standard deviation of the SAR distribution is 47%. The proliferation of the H4 cell line in 72 h in a pair of RF exposure-incubators reveals that the culture conditions are equivalent to

  8. SAGE II aerosol data validation based on retrieved aerosol model size distribution from SAGE II aerosol measurements

    NASA Technical Reports Server (NTRS)

    Wang, Pi-Huan; Mccormick, M. P.; Mcmaster, L. R.; Chu, W. P.; Swissler, T. J.; Osborn, M. T.; Russell, P. B.; Oberbeck, V. R.; Livingston, J.; Rosen, J. M.

    1989-01-01

    Consideration is given to aerosol correlative measurements experiments for the Stratospheric Aerosol and Gas Experiment (SAGE) II, conducted between November 1984 and July 1986. The correlative measurements were taken with an impactor/laser probe, a dustsonde, and an airborne 36-cm lidar system. The primary aerosol quantities measured by the ground-based instruments are compared with those calculated from the aerosol size distributions from SAGE II aerosol extinction measurements. Good agreement is found between the two sets of measurements.

  9. Volcanic Aerosol Radiative Properties

    NASA Technical Reports Server (NTRS)

    Lacis, Andrew

    2015-01-01

    Large sporadic volcanic eruptions inject large amounts of sulfur bearing gases into the stratosphere which then get photochemically converted to sulfuric acid aerosol droplets that exert a radiative cooling effect on the global climate system lasting for several years.

  10. The Airborne Cloud-Aerosol Transport System. Part I; Overview and Description of the Instrument and Retrival Algorithms

    NASA Technical Reports Server (NTRS)

    Yorks, John E.; Mcgill, Matthew J.; Scott, V. Stanley; Kupchock, Andrew; Wake, Shane; Hlavka, Dennis; Hart, William; Selmer, Patrick

    2014-01-01

    The Airborne Cloud-Aerosol Transport System (ACATS) is a multi-channel Doppler lidar system recently developed at NASA Goddard Space Flight Center (GSFC). A unique aspect of the multi-channel Doppler lidar concept such as ACATS is that it is also, by its very nature, a high spectral resolution lidar (HSRL). Both the particulate and molecular scattered signal can be directly and unambiguously measured, allowing for direct retrievals of particulate extinction. ACATS is therefore capable of simultaneously resolving the backscatterextinction properties and motion of a particle from a high altitude aircraft. ACATS has flown on the NASA ER-2 during test flights over California in June 2012 and science flights during the Wallops Airborne Vegetation Experiment (WAVE) in September 2012. This paper provides an overview of the ACATS method and instrument design, describes the ACATS retrieval algorithms for cloud and aerosol properties, and demonstrates the data products that will be derived from the ACATS data using initial results from the WAVE project. The HSRL retrieval algorithms developed for ACATS have direct application to future spaceborne missions such as the Cloud-Aerosol Transport System (CATS) to be installed on the International Space Station (ISS). Furthermore, the direct extinction and particle wind velocity retrieved from the ACATS data can be used for science applications such 27 as dust or smoke transport and convective outflow in anvil cirrus clouds.

  11. Influence of exhaled air on inhalation exposure delivered through a directed-flow nose-only exposure system.

    PubMed

    Moss, O R; James, R A; Asgharian, B

    2006-01-01

    In order to conserve material that is available in limited quantities, "directed-flow" nose-only exposure systems have at times been run at flow rates close to the minute ventilation of the animal. Such low-flow-rate conditions can contribute to a decrease of test substance concentration in inhaled air; near the animal nose, exhaled air and the directed flow of exposure air move in opposite directions. With a Cannon "directed-flow" nose-only exposure system (Lab Products, Maywood, NJ), we investigated the extent to which exposure air plus exhaled air can be inhaled by an animal. A mathematical model and a mechanical simulation of respiration were adopted to predict for a male Fischer 344 rat the concentration of test substance in inhaled air. The mathematical model was based on the assumption of instantaneous mixing. The mechanical simulation of respiration used a Harvard respirator. When the system was operated at an exposure air flow rate greater than 2.5 times the minute ventilation of the animal, the concentration of test substance in the inhaled air was reduced by less than 10%. Under these conditions, the circular jet of air exiting the exposure air delivery tube tended to reach the animal's nose with little dispersion. For exposure air flow rates less than 2 times the minute ventilation, we predict that the interaction of exhaled air and exposure air can be minimized by proportionally reducing the delivery tube diameter. These findings should be applicable to similar "directed-flow" nose-only exposure systems.

  12. The comprehensive model system COSMO-ART - radiative impact of aerosol on the state of the atmosphere on the regional scale

    NASA Astrophysics Data System (ADS)

    Vogel, B.; Vogel, H.; Bäumer, D.; Bangert, M.; Lundgren, K.; Rinke, R.; Stanelle, T.

    2009-07-01

    A new fully online coupled model system developed for the evaluation of the interaction of aerosol particles with the atmosphere on the regional scale is described. The model system is based on the operational weather forecast model of the Deutscher Wetterdienst. Physical processes like transport, turbulent diffusion, and dry and wet deposition are treated together with photochemistry and aerosol dynamics using the modal approach. Based on detailed calculations we have developed parameterizations to examine the impact of aerosol particles on photolysis and on radiation. Currently the model allows feedback between natural and anthropogenic aerosol particles and the atmospheric variables that are initialized by the modification of the radiative fluxes. The model system is applied to two summer episodes, each lasting five days, with a model domain covering Western Europe and adjacent regions. The first episode is characterised by almost cloud free conditions and the second one by cloudy conditions. The simulated aerosol concentrations are compared to observations made at 700 stations distributed over Western Europe. For each episode two model runs are performed; one where the feedback between the aerosol particles and the atmosphere is taken into account and a second one where the feedback is neglected. Comparing these two sets of model runs, the radiative feedback on temperature and other variables is evaluated. In the cloud free case a clear correlation between the aerosol optical depth and changes in global radiation and temperature is found. In the case of cloudy conditions the pure radiative effects are superposed by changes in the liquid water content of the clouds due to changes in the thermodynamics of the atmosphere. In this case the correlation between the aerosol optical depth and its effects on temperature is low. However, on average a decrease in the 2 m temperature is still found. In both cases a reduction in the daily temperature range, due to the

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

    NASA Astrophysics Data System (ADS)

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

    2011-12-01

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

  14. High throughput illumination systems for solar simulators and photoresist exposure

    NASA Astrophysics Data System (ADS)

    Feldman, Arkady

    2010-08-01

    High throughput illumination systems are critical component in photolithography, solar simulators, UV curing, microscopy, and spectral analysis. A good refractive condenser system has F/# .60, or N.A .80, but it captures only 10 to 15% of energy emitted by an incandescent or gas-discharge lamp, as these sources emit light in all directions. Systems with ellipsoidal or parabolic reflectors are much more efficient, they capture up to 80% of total energy emitted by lamps. However, these reflectors have large aberrations when working with real sources of finite dimensions, resulting in poor light concentrating capability. These aberrations also increase beam divergence, collimation, and affect edge definition in flood exposure systems. The problem is aggravated by the geometry of high power Arc lamps where, for thermal considerations, the anode has a larger diameter than the cathode and absorbs and obscures part of the energy. This results in an asymmetrical energy distribution emitted by the lamp and makes efficiency of Lamp - reflector configuration dependent on orientation of lamp in the reflector. This paper presents the analysis of different configurations of Lamp - Reflector systems of different power levels and their energy distribution in the image plane. Configuration, which results in significant improvement of brightness, is derived.

  15. Measurement systems and indices of miners' exposure to radon daughter products in the air of mines.

    PubMed

    Domański, T

    1990-01-01

    This paper presents the classification of measurement systems that may be used for the assessment of miners' exposure to radiation in mines. The following systems were described and characterized as the Air Sampling System (ASS), the Environmental Control System (ECS), the Individual Dosimetry System (IDS), the Stream Monitoring System (SMS) and the Exhaust Monitoring System (EMS). The indices for evaluation of miners' working environments, or for assessment of individual or collective miners' exposure, were selected and determined. These are: average expected concentration (CAE), average observed concentration (CAO), average expected rate of exposure cumulation rate (EEXP), average observed exposure cumulation rate (EOBS), average effective exposure cumulation rate (EEFF). Mathematical formulae for determining all these indicators, according to the type of measurement system used in particular mines, are presented. The reliability of assessment of miners' exposure in particular measurement systems, as well as the role of the possible reference system, are discussed. PMID:2134320

  16. HEDS - EPA DATABASE SYSTEM FOR PUBLIC ACCESS TO HUMAN EXPOSURE DATA

    EPA Science Inventory

    Human Exposure Database System (HEDS) is an Internet-based system developed to provide public access to human-exposure-related data from studies conducted by EPA's National Exposure Research Laboratory (NERL). HEDS was designed to work with the EPA Office of Research and Devel...

  17. Anthropogenic Aerosols and Tropical Precipitation

    NASA Astrophysics Data System (ADS)

    Wang, C.; Kim, D.; Ekman, A. M. L.; Barth, M. C.; Rasch, P. J.

    2009-04-01

    Anthropogenic aerosols can affect the radiative balance of the Earth-atmosphere system and precipitation by acting as cloud condensation nuclei (CCN) or ice nuclei (IN) and thus modifying the optical and microphysical properties as well as lifetimes of clouds. Recent studies have also suggested that the direct radiative effect of anthropogenic aerosols, particularly absorbing aerosols, can perturb the large-scale circulation and cause a significant change in both quantity and distribution of critical tropical precipitation systems ranging from Pacific and Indian to Atlantic Oceans. This effect of aerosols on precipitation often appears in places away from aerosol-concentrated regions and current results suggest that the precipitation changes caused by it could be much more substantial than that by the microphysics-based aerosol effect. To understand the detailed mechanisms and strengths of such a "remote impact" and the climate response/feedback to anthropogenic aerosols in general, an interactive aerosol-climate model has been developed based on the Community Climate System Model (CCSM) of NCAR. Its aerosol module describes size, chemical composition, and mixing states of various sulfate and carbonaceous aerosols. Several model processes are derived based on 3D cloud-resolving model simulations. We have conducted a set of long integrations using the model driven by radiative effects of different combinations of various carbonaceous and sulfate aerosols and their mixtures. The responses of tropical precipitation systems to the forcing of these aerosols are analyzed using both model and observational data. Detailed analyses on the aerosol-precipitation causal relations of two systems: i.e., the Indian summer monsoon and Pacific ITCZ will be specifically presented.

  18. SYSTEMIC IMBALANCE OF ESSENTIAL METALS AND CARDIAC GENE EXPRESSION IN RATS FOLLOWING ACUTE PULMONARY ZINC EXPOSURE

    EPA Science Inventory

    We have recently demonstrated that PM containing water-soluble zinc may cause cardiac injury following pulmonary exposure. To investigate if pulmonary zinc exposure causes systemic metal imbalance and direct cardiac effects, we intratracheally (IT) instilled male Wistar Kyoto (WK...

  19. [Development of a photoacoustic spectroscopy system for the measurement of absorption coefficient of atmospheric aerosols].

    PubMed

    Liu, Qiang; Niu, Ming-Sheng; Wang, Gui-Shi; Cao, Zhen-Song; Liu, Kun; Chen, Wei-Dong; Gao, Xiao-Ming

    2013-07-01

    In the present paper, the authors focus on the effect of the resonance frequency shift due to the changes in temperature and humidity on the PA signal, present several methods to control the noise derived form gas flow and vibration from the sampling pump. Based on the efforts mentioned above, a detection limit of 1.4 x 10(-8) W x cm(-1) x Hz(-1/2) was achieved for the measurement of atmospheric aerosols absorption coefficient. During the experiments, the PA cell was calibrated with the absorption of standard NO2 gas at 532 nm and the atmospheric aerosols were measured continuously. The measurement results show that the PAS is suitable for the real-time measurement of the absorption coefficient of atmospheric aerosols in their natural suspended state. PMID:24059163

  20. In-depth methods for systemic exposure predictions

    EPA Science Inventory

    Exposure to a wide range of chemicals is ubiquitous and largely unavoidable within modern society. The potential for human exposure, however, has not been quantified for the vast majority of chemicals with wide commercial use. Creative advances in exposure science are needed to s...

  1. Application of a global nonhydrostatic model with a stretched-grid system to regional aerosol simulations around Japan

    NASA Astrophysics Data System (ADS)

    Goto, D.; Dai, T.; Satoh, M.; Tomita, H.; Uchida, J.; Misawa, S.; Inoue, T.; Tsuruta, H.; Ueda, K.; Ng, C. F. S.; Takami, A.; Sugimoto, N.; Shimizu, A.; Ohara, T.; Nakajima, T.

    2014-01-01

    An aerosol-coupled global nonhydrostatic model with a stretched-grid system has been developed. Circulations over the global and target domains are simulated with a single model, which includes fine meshes covering the target region to calculate meso-scale circulations. The stretched global model involves relatively low computational costs to simulate atmospheric aerosols with fine horizontal resolutions compared with a global uniform nonhydrostatic model. As opposed to general regional models, neither a nesting technique nor boundary conditions are required. In this study, we developed a new air-quality model for the simulation of areas surrounding Tokyo, Japan, with a maximum horizontal resolution of approximately 10 km. We determined that this model was capable of simulating meteorological fields and anthropogenic primary particles, e.g., elemental carbon, and secondary particles, such as sulfate, with comparable results to those found with in-situ measurements and with other regional models. By combining the meteorological fields obtained from an atmosphere-ocean coupled model, we also applied the new model to a climate scenario experiment of PM2.5 (aerosol particles with diameters less than 2.5 μm) over Japan with a high horizontal resolution to assess the public health impact at the prefecture scale.

  2. Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration.

    PubMed

    Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H; Henry, Mike; Baden, Daniel G

    2010-05-01

    Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5-10 microg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m(3). The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction.

  3. Characterization of Florida red tide aerosol and the temporal profile of aerosol concentration

    PubMed Central

    Cheng, Yung Sung; Zhou, Yue; Pierce, Richard H.; Henry, Mike; Baden, Daniel G.

    2009-01-01

    Red tide aerosols containing aerosolized brevetoxins are produced during the red tide bloom and transported by wind to coastal areas of Florida. This study reports the characterization of Florida red tide aerosols in human volunteer studies, in which an asthma cohort spent 1 h on Siesta Beach (Sarasota, Florida) during aerosolized red tide events and non-exposure periods. Aerosol concentrations, brevetoxin levels, and particle size distribution were measured. Hourly filter samples were taken and analyzed for brevetoxin and NaCl concentrations. In addition, the aerosol mass concentration was monitored in real time. The results indicated that during a non-exposure period in October 2004, no brevetoxin was detected in the water, resulting in non-detectable levels of brevetoxin in the aerosol. In March 2005, the time-averaged concentrations of brevetoxins in water samples were moderate, in the range of 5–10 μg/L, and the corresponding brevetoxin level of Florida red tide aerosol ranged between 21 and 39 ng/m3. The temporal profiles of red tide aerosol concentration in terms of mass, NaCl, and brevetoxin were in good agreement, indicating that NaCl and brevetoxins are components of the red tide aerosol. By continuously monitoring the marine aerosol and wind direction at Siesta Beach, we observed that the marine aerosol concentration varied as the wind direction changed. The temporal profile of the Florida red tide aerosol during a sampling period could be explained generally with the variation of wind direction. PMID:19879288

  4. An Exposure Prevention Plan for an Anhydrous Ammonia Handling System

    NASA Technical Reports Server (NTRS)

    Padolewski, Cathy L.; Bower, Amy; Ponikvar, Gary; Mellott, Ken

    1997-01-01

    In July of 1996, the Industrial Hygiene Team of the Environmental Management Office at NASA Lewis Research Center was contacted by the Space Station Program Office to conduct ammonia awareness training for a team of engineers and technicians. The team was tasked with assembling and operating an ammonia handling system for testing of a photovoltaic radiator at the NASA Plum Brook Station Space Power Facility. The ammonia handling system supports a radiator designed to radiate excess heat from a photovoltaic array module used to provide power to the International Space Station. The system would consist of a hazardous materials trailer equipped with an anhydrous ammonia tank, heater, accumulator, chiller, and flow bench. Meetings were held with representatives from the Space Station Program Office, the engineers and Plum Brook safety personnel. Guidance was also provided by representatives from Kennedy Space Center. Determinations were made concerning the locations and types of potential exposures and a plan was developed which included training, personal protective equipment, engineering controls and emergency response. Various organizations including the Plum Brook Safety Committee, the Lewis Environmental Management Office, the Test Readiness Review Board and the Program Office all had requirements that had to be met in order to satisfy themselves that all personnel involved in the operation of the system would be safe. What resulted was a comprehensive plan that provided more than adequate safety measures and succeeded in protecting all personnel from the hazards of the ammonia system. Testing of the photovoltaic radiator was successful and although ammonia leaks were detected and maintenance of the system was ongoing, no one was injured. It was felt that the training and controls in place allowed for a comfort level that did not interfere with the operations.

  5. Poisonings Associated with Intubation: US National Poison Data System Exposures 2000-2013.

    PubMed

    Beauchamp, G A; Giffin, S L; Horowitz, B Z; Laurie, A L; Fu, R; Hendrickson, R G

    2016-06-01

    Patients may be intubated after exposure to a variety of substances because of respiratory failure, CNS sedation, pulmonary pathology, or cardiovascular instability. However, there is little data describing the types of substances that are associated with endotracheal intubation or the rates of intubation after these exposures. Evaluation of this association may inform future research on intubation after exposures to specific substances and guide poison prevention education. Our objective was to determine which exposures were commonly associated with intubation using the data from National Poison Data System (NPDS). The NPDS tracks data from potential exposures to substances reported to all American Association of Poison Control Centers. We performed a retrospective analysis of NPDS data from January 1st, 2000 to December 31st, 2013 to identify human exposures to substances that were associated with endotracheal intubation. Descriptive statistics were used to analyze the data. There were 93,474 single substance exposures and 228,507 multiple substance exposures that were associated with intubation. The most common exposures to substances that were associated with intubation were atypical antipsychotics (7.4 %) for single exposures and benzodiazepines (27.4 %) for multiple exposures. Within each age group, the most common known exposures to substances were for patients under 6 years, clonidine for single and multiple exposures; for patients aged 6-12 years, clonidine for single exposures and atypical antipsychotics for multiple exposures; for patients aged 13-19 years, atypical antipsychotics for single and multiple exposures; and for patients over 19 years, atypical antipsychotics for single exposures and benzodiazepines for multiple exposures. From 2000-2013, the exposures to substances most commonly associated with intubation varied by single versus multiple exposures and by age. This study helps clarify the exposures to substances that are associated with

  6. Developing a model system for studying the ozone processing of atmospheric aerosols by following changes in surface properties

    NASA Astrophysics Data System (ADS)

    Gonzalez-Labrada, Erick

    Atmospheric aerosols have a significant organic composition as determined by field measurement studies. This organic material is released to the atmosphere from both natural and anthropogenic sources, such as wind bursting of the ocean surface, car exhausts, and meat cooking, among others. An inverted micelle model has been proposed in order to explain the high concentration of organic compounds in aerosol particles. The model describes an organic film coating the air-liquid interface of an aqueous aerosol core. Chemical processing of this organic film by atmospheric oxidants (such as OH radicals, O3, and NO3) through heterogeneous and multiphase reactions can activate the aerosol to participate in atmospheric chemistry. After reaction, the particle has an increased role in the absorption and scattering of incoming solar radiation and cloud formation. Another consequence of this oxidation is the decrease of the atmospheric budget of gas-phase trace species, as well as the formation of volatile products. Several studies have proposed that the ozonolysis of organic films in aerosols takes place mainly at the surface. Therefore, the objective of this research was to develop a suitable model system for following the reaction through quantitative changes of a property inherent to the surface. Several attempts were made to examine the ozonolysis of organic monolayers at either solid or liquid surfaces. The studied monolayers contained unsaturated organic compounds as the only component or as part of a binary mixture with saturated compounds. The study of the ozone processing of monolayers deposited on solid substrates revealed information about changes in the hydrophobic character of the surface that occurred because of the reaction. On the other hand, the processing of a monolayer spread on a pendant drop allowed a real-time monitoring of surface pressure changes. This permitted a kinetic study of the reaction that yielded parameters related exclusively to processes

  7. MULTICOMPONENT AEROSOL DYNAMICS OF THE PB-O2 SYSTEM IN A BENCH SCALE FLAME INCINERATOR

    EPA Science Inventory

    A study was carried out to understand the formation and growth of lead particles in a flame incinerator. A bench scale flame incinerator was used to perform controlled experiments with lead acetate as a test compound. A dilution probe in conjunction with real-time aerosol instrum...

  8. Simulations of the observation of clouds and aerosols with the Experimental Lidar in Space Equipment system.

    PubMed

    Liu, Z; Voelger, P; Sugimoto, N

    2000-06-20

    We carried out a simulation study for the observation of clouds and aerosols with the Japanese Experimental Lidar in Space Equipment (ELISE), which is a two-wavelength backscatter lidar with three detection channels. The National Space Development Agency of Japan plans to launch the ELISE on the Mission Demonstrate Satellite 2 (MDS-2). In the simulations, the lidar return signals for the ELISE are calculated for an artificial, two-dimensional atmospheric model including different types of clouds and aerosols. The signal detection processes are simulated realistically by inclusion of various sources of noise. The lidar signals that are generated are then used as input for simulations of data analysis with inversion algorithms to investigate retrieval of the optical properties of clouds and aerosols. The results demonstrate that the ELISE can provide global data on the structures and optical properties of clouds and aerosols. We also conducted an analysis of the effects of cloud inhomogeneity on retrievals from averaged lidar profiles. We show that the effects are significant for space lidar observations of optically thick broken clouds.

  9. Phase-contrast helium-3 MRI of aerosol deposition in human airways.

    PubMed

    Sarracanie, Mathieu; Grebenkov, Denis; Sandeau, Julien; Coulibaly, Soulé; Martin, Andrew R; Hill, Kyle; Pérez Sánchez, José Manuel; Fodil, Redouane; Martin, Lionel; Durand, Emmanuel; Caillibotte, Georges; Isabey, Daniel; Darrasse, Luc; Bittoun, Jacques; Maître, Xavier

    2015-02-01

    One of the key challenges in the study of health-related aerosols is predicting and monitoring sites of particle deposition in the respiratory tract. The potential health risks of ambient exposure to environmental or workplace aerosols and the beneficial effects of medical aerosols are strongly influenced by the site of aerosol deposition along the respiratory tract. Nuclear medicine is the only current modality that combines quantification and regional localization of aerosol deposition, and this technique remains limited by its spatial and temporal resolutions and by patient exposure to radiation. Recent work in MRI has shed light on techniques to quantify micro-sized magnetic particles in living bodies by the measurement of associated static magnetic field variations. With regard to lung MRI, hyperpolarized helium-3 may be used as a tracer gas to compensate for the lack of MR signal in the airways, so as to allow assessment of pulmonary function and morphology. The extrathoracic region of the human respiratory system plays a critical role in determining aerosol deposition patterns, as it acts as a filter upstream from the lungs. In the present work, aerosol deposition in a mouth-throat phantom was measured using helium-3 MRI and compared with single-photon emission computed tomography. By providing high sensitivity with high spatial and temporal resolutions, phase-contrast helium-3 MRI offers new insights for the study of particle transport and deposition.

  10. Reducing exposures during the pouring operations of a brass foundry.

    PubMed

    Edmonds, M A; Gressel, M G; O'Brien, D M; Clark, N J

    1993-05-01

    The focus of this exposure assessment and control technology study was a brass foundry and the lead exposures of workers involved in the transportation and pouring of metal. Controls in place at the foundry included ventilation systems at the furnace and along the continuous and stationary pouring lines. Real-time measurements were made to determine which tasks were the primary exposure sources, and a hand-held aerosol monitor was used to measure real-time aerosol exposures (as a surrogate for lead) in the workers' breathing zones. Data were collected over two 30-min sampling periods while worker activities were monitored using a video camera. Analysis of the data showed that the greatest aerosol exposures occurred during the transportation of an unventilated, full ladle, resulting in an average concentration of at least twice that of the other tasks. The study concluded that the addition of exhaust ventilation such as a moveable hood and duct system during the ladle transport and pouring tasks, and the implementation of a side draft hood at the pigging area, could result in a reduction of worker exposure to aerosols during the continuous pouring operation by up to 40%. The controls and techniques suggested in this study could be applied to pouring operations throughout the industry to reduce worker exposure to metal fumes.

  11. Short exposure to telestereoscope affects the oculomotor system.

    PubMed

    Neveu, Pascaline; Priot, Anne-Emmanuelle; Plantier, Justin; Roumes, Corinne

    2010-11-01

    Under natural viewing conditions, the accommodation and vergence systems adjust the focus and the binocular alignment of the eyes in response to changes in viewing distance. The two responses are linked via cross-coupling and proceed almost simultaneously. Some optical devices, such as virtual reality or helmet mounted displays, create an oculomotor conflict by modifying demands on both vergence and accommodation. Previous studies extensively investigated the effect of such a conflict on the cross-coupling between vergence and accommodation, but little is known about the plasticity of the whole oculomotor system. In the present study, an oculomotor conflict was induced by a telestereoscope which magnified the standard inter-pupillary separation threefold and thus increased the convergence demand while accommodation remained almost unchanged. The effect of a 10 min exposure was assessed via a series of optometric parameters selected on the basis of existing oculomotor models. Associated with subject's visual complaints, most of the oculomotor parameters tested were modified: there was (1) deterioration of stereoscopic threshold; (2) increase in AC/A ratio; (3) increase in near and far phorias; and (4) shift of the zone of clear and single binocular vision towards convergence. These results showed a change in gain of accommodative vergence and a shift of vergence reserves towards convergence in response to telestereoscopic viewing. The subject's binocular behaviour tended towards esophoria with convergence excess as confirmed by Sheard's and Percival's criteria. Such changes in oculomotor parameters support adaptive behaviour linked with telestereoscopic viewing.

  12. THE HUMAN EXPOSURE DATABASE SYSTEM (HEDS)-PUTTING THE NHEXAS DATA ON-LINE

    EPA Science Inventory

    The EPA's National Exposure Research Laboratory (NERL) has developed an Internet accessible Human Exposure Database System (HEDS) to provide the results of NERL human exposure studies to both the EPA and the external scientific communities. The first data sets that will be ava...

  13. Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering. 1992 Annual summary

    SciTech Connect

    Aker, P.M.

    1993-01-30

    This study is aimed at characterizing the influence of aerosol surface structure on the kinetics of gas-aerosol interactions. Changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol are measured with aerosols having different surface properties due to the composition and/or temperature of the material making up the aerosol. The kinetic data generated can be used directly in atmospheric modeling calculations. The surface structure of the aerosol is using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during, the course of the reaction. This dynamics information can be used to generate kinetic data for systems which are similar in nature to those studied, but are not amenable to laboratory investigation. We show here that increased MDSRS sensitivity is achieved by using an excitation laser source that has a narrow linewidth and we have been able to detect sulfate anion concentrations much lower than previously reported. We have shown that the linewidth of the MDSRS mode excited in a droplet is limited by the laser linewidth. This is a positive result for it eases our ability to quantify the MDSRS gain equation. This result also suggests that MDSRS signal size should be independent of droplet size, and preliminary experiments confirm this hypothesis.

  14. Characterization of gas-aerosol interaction kinetics using morphology dependent stimulated Raman scattering

    SciTech Connect

    Aker, P.M.

    1993-01-30

    This study is aimed at characterizing the influence of aerosol surface structure on the kinetics of gas-aerosol interactions. Changes in gas phase chemical reaction rates as a function of exposure to a specific aerosol are measured with aerosols having different surface properties due to the composition and/or temperature of the material making up the aerosol. The kinetic data generated can be used directly in atmospheric modeling calculations. The surface structure of the aerosol is using morphology-dependent enhancement of simulated Raman scattering (MDSRS). Detailed dynamics of gas-aerosol interactions can be obtained by correlating the change in the reaction rate with change in surface structure and by monitoring the change in aerosol surface structure during, the course of the reaction. This dynamics information can be used to generate kinetic data for systems which are similar in nature to those studied, but are not amenable to laboratory investigation. We show here that increased MDSRS sensitivity is achieved by using an excitation laser source that has a narrow linewidth and we have been able to detect sulfate anion concentrations much lower than previously reported. We have shown that the linewidth of the MDSRS mode excited in a droplet is limited by the laser linewidth. This is a positive result for it eases our ability to quantify the MDSRS gain equation. This result also suggests that MDSRS signal size should be independent of droplet size, and preliminary experiments confirm this hypothesis.

  15. ATI TDA 5A aerosol generator evaluation

    SciTech Connect

    Gilles, D.A.

    1998-07-27

    Oil based aerosol ``Smoke`` commonly used for testing the efficiency and penetration of High Efficiency Particulate Air filters (HEPA) and HEPA systems can produce flammability hazards that may not have been previously considered. A combustion incident involving an aerosol generator has caused an investigation into the hazards of the aerosol used to test HEPA systems at Hanford.

  16. Proposed alternatives for a DOE-wide occupational radiation exposure information system

    SciTech Connect

    Murphy, B.L.; Murphy, D.W.; Fix, J.J.; Selby, J.M.; Vallario, E.J.

    1984-02-01

    The Radiation Exposure Information Reporting System (REIRS) was initiated by the Atomic Energy Commission (AEC) in 1968. While the system has provided a general overview of radiation exposures associated with AEC/ERDA/DOE operations and has satisfied the original intent for a central information system, the need for more detailed information has become evident. The alternatives addressed for a radiation exposure information system were no change in current system, clarification of DOE Order for current system, increased summary information from sites, centralized annual individual dose (exposure) system, and annual dose summary and locator files. A majority of the DOE Ad Hoc Committee has concurred to recommend the annual dose summary and locator files (ADSLF). The acceptance of the ADSLF alternative as the DOE-wide radiation exposure system would give DOE added capability and flexibility in responding to requests for information and would reduce the impact on the sites of special survey requests.

  17. Surface-Sensitive and Bulk Studies on the Complexation and Photosensitized Degradation of Catechol by Iron(III) as a Model for Multicomponent Aerosol Systems

    NASA Astrophysics Data System (ADS)

    Al-abadleh, H. A.; Tofan-Lazar, J.; Situm, A.; Ruffolo, J.; Slikboer, S.

    2013-12-01

    Surface water plays a crucial role in facilitating or inhibiting surface reactions in atmospheric aerosols. Little is known about the role of surface water in the complexation of organic molecules to transition metals in multicomponent aerosol systems. We will show results from real time diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) experiments for the in situ complexation of catechol to Fe(III) and its photosensitized degradation under dry and humid conditions. Catechol was chosen as a simple model for humic-like substances (HULIS) in aerosols and aged polyaromatic hydrocarbons (PAH). It has also been detected in secondary organic aerosols (SOA) formed from the reaction of hydroxyl radicals with benzene. Given the importance of the iron content in aerosols and its biogeochemistry, our studies were conducted using FeCl3. For comparison, these surface-sensitive studies were complemented with bulk aqueous ATR-FTIR, UV-vis, and HPLC measurements for structural, quantitative and qualitative information about complexes in the bulk, and potential degradation products. The implications of our studies on understanding interfacial and condensed phase chemistry relevant to multicomponent aerosols, water thin islands on buildings, and ocean surfaces containing transition metals will be discussed.

  18. Role of anthropogenic aerosols in the20th century surface solar radiation, temperature, and meridional heat transport in the Max Planck Earth System Model

    NASA Astrophysics Data System (ADS)

    Dallafior, Tanja; Folini, Doris; Knutti, Reto; Wild, Martin

    2016-04-01

    It is still debated, to what degree anthropogenic aerosols were affected surface temperatures - especially over sea surfaces - through alteration of surface solar radiation (SSR). Previous work using mixed-layer ocean equilibria corroborated the relevance of anthropogenic aerosols for surface temperature response patterns obtained. Here we complement these studies by fully coupled simulations with the Max Planck Earth System Model (MPI-ESM) in its CMIP5 version. Experiments comprise preindustrial control and historical as in CMIP5, as well as transient experiments 1850 - 2000 with either anthropogenic aerosols or well-mixed greenhouse gases (WMGHG) kept at 1850 levels. With this suite of experiments, we analyse the impact of anthropogenic aerosols and WMGHG on the global energy balance and provide estimates of atmospheric and oceanic meridional heat transport changes in our modeling setup. We find that Global mean surface temperature responses to single forcings are additive. Furthermore, spatial surface temperature response patterns in the WMGHG only experiment are more strongly correlated with the historical experiment than the aerosol only case. We compare transient and equilibrium responses and discuss potential implications of not allowing for cloud-aerosol interactions in the transient modeling set-up.

  19. Theoretical and global scale model studies of the atmospheric sulfur/aerosol system

    NASA Technical Reports Server (NTRS)

    Kasibhatla, Prasad

    1996-01-01

    The primary focus during the third-phase of our on-going multi-year research effort has been on 3 activities. These are: (1) a global-scale model study of the anthropogenic component of the tropospheric sulfur cycle; (2) process-scale model studies of the factors influencing the distribution of aerosols in the remote marine atmosphere; and (3) an investigation of the mechanism of the OH-initiated oxidation of DMS in the remote marine boundary layer. In this paper, we describe in more detail our research activities in each of these areas. A major portion of our activities during the fourth and final phase of this project will involve the preparation and submission of manuscripts describing the results from our model studies of marine boundary-layer aerosols and DMS-oxidation mechanisms.

  20. Why Is Improvement of Earth System Models So Elusive? Challenges and Strategies From Dust Aerosol Modeling

    NASA Astrophysics Data System (ADS)

    Miller, R. L.; Pérez García-Pando, C.; Perlwitz, J. P.; Ginoux, P. A.

    2015-12-01

    Past decades have seen an accelerating increase in computing efficiency,while climate models are representing a rapidly widening set ofphysical processes. Yet simulations of some fundamental aspects ofclimate like precipitation or aerosol forcing remain highly uncertainand resistent to progress. Dust aerosol modeling of soil particleslofted by wind erosion has seen a similar conflict between increasingmodel sophistication and remaining uncertainty. Dust aerosols perturbthe energy and water cycles by scattering radiation and acting as icenuclei, while mediating atmospheric chemistry and marinephotosynthesis (and thus the carbon cycle). These effects take placeacross scales from the dimensions of an ice crystal to theplanetary-scale circulation that disperses dust far downwind of itsparent soil. Representing this range leads to several modelingchallenges. Should we limit complexity in our model, which consumescomputer resources and inhibits interpretation? How do we decide if aprocess involving dust is worthy of inclusion within our model? Canwe identify a minimal representation of a complex process that isefficient yet retains the physics relevant to climate? Answeringthese questions about the appropriate degree of representation isguided by model evaluation, which presents several more challenges.How do we proceed if the available observations do not directlyconstrain our process of interest? (This could result from competingprocesses that influence the observed variable and obscure thesignature of our process of interest.) Examples will be presentedfrom dust modeling, with lessons that might be more broadlyapplicable. The end result will either be clinical depression or thereassuring promise of continued gainful employment as the communityconfronts these challenges.

  1. Aerosol - cloud - water vapor relations for cloud systems of different heights

    NASA Astrophysics Data System (ADS)

    Stathopoulos, Stavros; Kourtidis, Konstantinos; Georgoulias, Aristeidis

    2016-04-01

    Here we examine the annual and seasonal aerosol - cloud relations over three major urban clusters of China, for different cloud heights and atmospheric water vapor amounts, using a decade of Aerosol Optical Depth at 550nm (AOD), Cloud Cover (CC), Cloud Optical Depth (COD), Water Vapor (WV) and Cloud Top Pressure (CTP) data from the MODIS instrument. Over all regions (spanning from temperate to tropical monsoon climates) and for all seasons, CC is found to increase with AOD, WV and cloud height. Aerosols, at low WV environments and under constant cloud height, have less impact on CC than at high WV environments. In addition, AOD has a varying influence on COD depending on CTP. Finally, COD is found to increase with height for low and middle height clouds, and with increasing AOD, especially at low AOD, the latter being in line with the expected first indirect effect. This research has been financed under the FP7 Programme MarcoPolo (Grand Number 606953, Theme SPA.2013.3.2-01).

  2. Occupational exposures and risk of systemic lupus erythematosus.

    PubMed

    Parks, Christine G; Cooper, Glinda S

    2005-11-01

    This review summarizes the growing body of epidemiologic and experimental research pertaining to the relationship between SLE and occupational exposures, such as crystalline silica, solvents, and pesticides. Epidemiologic studies, using different designs in different settings, have demonstrated moderate to strong associations between occupational silica exposure and SLE. Recent experimental studies of silica in lupus-prone mice provide support for the idea that, in addition to its known adjuvant effect, silica exposure increases the generation of apoptotic material, an important source of self-antigen. Despite compelling experimental studies of the organic solvent trichloroethylene (TCE) in lupus-prone mice, there is little evidence of an overall association of SLE and occupational exposure to a broad classification of solvents in humans. However, there is a lack of data on SLE in occupational cohorts with exposures to TCE or other specific solvents. One epidemiologic study reported an association of pesticide mixing and SLE, while a recent experimental study reported accelerated disease in pesticide-treated lupus-prone mice. Other occupational exposures worth investigating include asbestos, metals, and UV radiation. Attention should also be given to the role of gene-environment interactions, which may require large, multi-site studies that collect both genetic material and occupational exposure data. The quality of exposure assessment is an important consideration in designing and evaluating these studies. The use of pre-clinical endpoints (e.g. high-titer autoantibodies) in occupational cohorts with well-characterized exposure histories may reveal occupational risk factors for autoimmunity, and may also provide baseline data for studies of determinants of progression to SLE.

  3. The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics.

    PubMed

    Chen, Chun; Zhao, Bin; Cui, Weilin; Dong, Lei; An, Na; Ouyang, Xiangying

    2010-07-01

    Dental healthcare workers (DHCWs) are at high risk of occupational exposure to droplets and aerosol particles emitted from patients' mouths during treatment. We evaluated the effectiveness of an air cleaner in reducing droplet and aerosol contamination by positioning the device in four different locations in an actual dental clinic. We applied computational fluid dynamics (CFD) methods to solve the governing equations of airflow, energy and dispersion of different-sized airborne droplets/aerosol particles. In a dental clinic, we measured the supply air velocity and temperature of the ventilation system, the airflow rate and the particle removal efficiency of the air cleaner to determine the boundary conditions for the CFD simulations. Our results indicate that use of an air cleaner in a dental clinic may be an effective method for reducing DHCWs' exposure to airborne droplets and aerosol particles. Further, we found that the probability of droplet/aerosol particle removal and the direction of airflow from the cleaner are both important control measures for droplet and aerosol contamination in a dental clinic. Thus, the distance between the air cleaner and droplet/aerosol particle source as well as the relative location of the air cleaner to both the source and the DHCW are important considerations for reducing DHCWs' exposure to droplets/aerosol particles emitted from the patient's mouth during treatments.

  4. The effectiveness of an air cleaner in controlling droplet/aerosol particle dispersion emitted from a patient's mouth in the indoor environment of dental clinics

    PubMed Central

    Chen, Chun; Zhao, Bin; Cui, Weilin; Dong, Lei; An, Na; Ouyang, Xiangying

    2010-01-01

    Dental healthcare workers (DHCWs) are at high risk of occupational exposure to droplets and aerosol particles emitted from patients' mouths during treatment. We evaluated the effectiveness of an air cleaner in reducing droplet and aerosol contamination by positioning the device in four different locations in an actual dental clinic. We applied computational fluid dynamics (CFD) methods to solve the governing equations of airflow, energy and dispersion of different-sized airborne droplets/aerosol particles. In a dental clinic, we measured the supply air velocity and temperature of the ventilation system, the airflow rate and the particle removal efficiency of the air cleaner to determine the boundary conditions for the CFD simulations. Our results indicate that use of an air cleaner in a dental clinic may be an effective method for reducing DHCWs' exposure to airborne droplets and aerosol particles. Further, we found that the probability of droplet/aerosol particle removal and the direction of airflow from the cleaner are both important control measures for droplet and aerosol contamination in a dental clinic. Thus, the distance between the air cleaner and droplet/aerosol particle source as well as the relative location of the air cleaner to both the source and the DHCW are important considerations for reducing DHCWs' exposure to droplets/aerosol particles emitted from the patient's mouth during treatments. PMID:20031985

  5. A Ground-Based 2-Micron DIAL System to Profile Tropospheric CO2 and Aerosol Distributions for Atmospheric Studies

    NASA Technical Reports Server (NTRS)

    Ismail, Syed; Koch, Grady; Abedin, Nurul; Refaat, Tamer; Rubio, Manuel; Davis, Kenneth; Miller, Charles; Singh, Upendra

    2006-01-01

    System will operate at a temperature insensitive CO2 line (2050.967 nm) with side-line tuning and off-set locking. Demonstrated an order of magnitude improvement in laser line locking needed for high precision measurements, side-line operation, and simultaneously double pulsing and line locking. Detector testing of phototransistor has demonstrated sensitivity to aerosol features over long distances in the atmosphere and resolve features approx. 100m. Optical systems that collect light onto small area detectors work well. Receiver optical designs are being optimized and data acquisition systems developed. CO2 line parameter characterization in progress In situ sensor calibration in progress for validation of DIAL CO2 system.

  6. Aerosols-cloud-climate -interactions in the Norwegian Earth System Model (NorESM). Importance of biogenic particles for cloud properties and anthropogenic indirect effect.

    NASA Astrophysics Data System (ADS)

    Seland, Ø.; Iversen, T.; Kirkevâg, A.

    2012-04-01

    According to the 4th assessment report of IPCC, major sources of uncertainty in anthropogenic climate change projections are inaccurate model description and weak knowledge of aerosols and their interactions with radiation and clouds, as well as the cloud feedback to radiative forcing. One important aspect of the associated uncertainty is the natural atmosphere. Anthropogenic climate change is an increment caused by anthropogenic emissions relative to the properties of the climate system untouched by man. This is crucial for the direct and indirect effects of aerosols, since the amount, size and physical properties of natural background particles strongly influence the same properties of the anthropogenic aerosol components. In many climate models where CDNC is calculated explicitly, CDNC is constrained by prescribing a lower bound below which calculated values are not allowed. This is done in order to keep the aerosol in-direct effect within estimated values. The rationale for using such a lower bound is to keep the aerosol radiative forcing constrained by the forcing of green-house gases and 20th century climate.We hypothesize this lower bound can be removed or made less strict by including aerosols of biogenic origin. We will present results and sensitivity studies from simulations with the NorESM where we have added contributions from organic carbon of natural origin both from vegetation and oceanic sources. By including aerosols of biogenic origin we obtain close to the median indirect radiative forcing reported by IPCC AR4, as well as reproducing the temperature increase in the 20th century. NorESM is based on the Earth system model CCSM4.0 from NCAR, but is using CAM4-Oslo instead of CAM4 as atmosphere model and an updated version of MICOM from the Bergen Climate Model (BCM) instead of the ocean model POP2. The aerosol module includes sea-salt, dust, sulphate, black carbon (BC) and particulate organic matter (OM). Primary aerosol size-distributions are

  7. Prandial effect on the systemic exposure of amisulpride.

    PubMed

    Jang, Yoo-Jung; Jeong, Tae Cheon; Noh, Keumhan; Baek, In-Whan; Kwon, Kwang-il; Kim, Eunyoung; Yoon, Young-Ran; Kang, Wonku

    2014-10-01

    A substituted benzamide, amisulpride is an atypical antipsychotic and a specific antagonist for dopamine D2 and D3 receptors. The prandial effect on amisulpride absorption remains unclear, therefore, this study was designed to investigate the effect of food on the systemic exposure to amisulpride in healthy volunteers. The study was a randomized, two-way crossed trial in which a single oral dose of amisulpride was administered on two occasions, with 7-days washout period between each drug administration. The volunteers were randomly divided into two groups and received amisulpride (50 mg) with Korean traditional food or under fasting state. Blood was serially taken, and the plasma amisulpride concentrations were measured by LC/MS/MS. At fasting state, amisulpride reached the first peak (37.1 ± 13.3 ng/ml) at ~2.3 h, and decreased down to 19.4 ± 4.3 ng/ml until 3.5 h, and then again went up to the second peak (25.3 ± 5.8 ng/ml) at 5 h followed by a slow decay with 10.6 h of half-life. In contrast, no double peaks were shown when the drug was given with meal. The maximum concentration of amisulpride (56.0 ± 12.7 ng/ml) was increased by a 1.5-fold compared with that under fasting (p > 0.05), and the time to peak shortened a little (1.7 ± 0.6 h).

  8. Lidar and Laser Technology for NASA'S Cloud-Aerosol Transport System (CATS) Payload on The International Space Station (JEM-EF)

    NASA Astrophysics Data System (ADS)

    Storm, Mark; Stevenson, Gary; Hovis, Floyd; Gavert, William; Dang, Xung; Darab, Abe; Chuang, Ti; Burns, Patrick

    2016-06-01

    This paper describes the ISS lidar technology provided by Fibertek, Inc. in support of the NASA GSFC CATS mission and provides an assessment of the in-flight systems performance and lessons learned. During February the systems successfully operated in space for more than 300 hours using 25 W average power lasers and photon counting of aerosol atmospheric returns.

  9. Aerosol delivery of programmed cell death protein 4 using polysorbitol-based gene delivery system for lung cancer therapy.

    PubMed

    Kim, You-Kyoung; Xing, Lei; Chen, Bao-An; Xu, Fengguo; Jiang, Hu-Lin; Zhang, Can

    2014-11-01

    The development of a safe and effective gene delivery system is the most challenging obstacle to the broad application of gene therapy in the clinic. In this study, we report the development of a polysorbitol-based gene delivery system as an alternative gene carrier for lung cancer therapy. The copolymer was prepared by a Michael addition reaction between sorbitol diacrylate (SD) and spermine (SPE); the SD-SPE copolymer effectively condenses with DNA on the nanoscale and protects it from nucleases. SD-SPE/DNA complexes showed excellent transfection with low toxicity both in vitro and in vivo, and aerosol delivery of SD-SPE complexes with programmed cell death protein 4 DNA significantly suppressed lung tumorigenesis in K-ras(LA1) lung cancer model mice. These results demonstrate that SD-SPE has great potential as a gene delivery system based on its excellent biocompatibility and high gene delivery efficiency for lung cancer gene therapy. PMID:24983766

  10. Global Aerosols

    Atmospheric Science Data Center

    2013-04-19

    ... sizes and from multiple sources, including biomass burning, mineral dust, sea salt and regional industrial pollution. A color scale is ... desert source region. Deserts are the main sources of mineral dust, and MISR obtains aerosol optical depth at visible wavelengths ...