Science.gov

Sample records for airborne radioactive particles

  1. Sampling for Airborne Radioactivity

    DTIC Science & Technology

    2007-10-01

    compared to betas, gammas and neutrons. For an airborne radioactivity detection system, it is most important to be able to detect alpha particles and... Airborne radioactive particles may emit alpha, beta, gamma or neutron radiation, depending on which radioisotope is present. From a health perspective...

  2. Airborne Particles.

    ERIC Educational Resources Information Center

    Ojala, Carl F.; Ojala, Eric J.

    1987-01-01

    Describes an activity in which students collect airborne particles using a common vacuum cleaner. Suggests ways for the students to convert their data into information related to air pollution and human health. Urges consideration of weather patterns when analyzing the results of the investigation. (TW)

  3. Dynamic radioactive particle source

    DOEpatents

    Moore, Murray E; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  4. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  5. Automatic Searching Radioactive Sources by Airborne Radioactive Survey Using Multicopter

    NASA Astrophysics Data System (ADS)

    Rim, H.; Eun, S. B.; Kim, K.; Park, S.; Jung, H. K.

    2015-12-01

    In order to prepare emergency situation lost a dangerous radioelement source in advance and to search a radioactive source automatically, we develop airborne radioelement survey system by multicopter. This multicopter radioelement survey system consists of a small portable customized BGO (Bismuth Germanate Oxide) detector, video recording part, wireless connecting part to ground pilot, GPS, and several equipments for automatic flight. This system is possible to search flight by preprogramed lines. This radioactive detecting system are tested to find intentional hidden source, The performance of detecting a source is well proved with very low flight altitude in spite of depending on the magnitude of radioelement sources. The advantage of multicopter system, one of UAV (Unmanned Aerial Vehicle), is to avoid the potential of close access to a dangerous radioactive source by using fully automatic searching capability. In this paper, we introduce our multicopter system for detecting radioactive source and synthetic case history for demonstrating this system.

  6. Experience with airborne detection of radioactive pollution (ENMOS, IRIS).

    PubMed

    Pavlik, Bohuslav; Engelsmann, Jan

    2004-01-01

    This paper discusses the advantages of airborne monitoring of radioactive pollution and shows example maps indicating manmade pollution from different sources. The sensitivity of airborne radioactive detection is discussed. Comparisons of airborne and different ground measurements are presented. New instrumentation for airborne or ground moving vehicles is briefly described. Airborne footprinting provides rapid, well-defined spatial images of natural and manmade radioactive contamination. Data acquisition integrated with GPS navigation provides consistent data and guarantees proper data location. Real-time airborne measurements are re-calculated, with the use of special algorithms, into absolute units for individual radioactive nuclei contamination of the ground together with dose calculation. Raw records and calculated data are provided after enhanced post-flight processing. Dose rates and detection of different radioactive elements are presented. (ENMOS is a product of Picodas Group Inc. and IRIS is the product of Pico Envirotec Inc.)

  7. Effects of particle size and velocity on burial depth of airborne particles in glass fiber filters

    SciTech Connect

    Higby, D.P.

    1984-11-01

    Air sampling for particulate radioactive material involves collecting airborne particles on a filter and then determining the amount of radioactivity collected per unit volume of air drawn through the filter. The amount of radioactivity collected is frequently determined by directly measuring the radiation emitted from the particles collected on the filter. Counting losses caused by the particle becoming buried in the filter matrix may cause concentrations of airborne particulate radioactive materials to be underestimated by as much as 50%. Furthermore, the dose calculation for inhaled radionuclides will also be affected. The present study was designed to evaluate the extent to which particle size and sampling velocity influence burial depth in glass-fiber filters. Aerosols of high-fired /sup 239/PuO/sub 2/ were collected at various sampling velocities on glass-fiber filters. The fraction of alpha counts lost due to burial was determined as the ratio of activity detected by direct alpha count to the quantity determined by photon spectrometry. The results show that burial of airborne particles collected on glass-fiber filters appears to be a weak function of sampling velocity and particle size. Counting losses ranged from 0 to 25%. A correction that assumes losses of 10 to 15% would ensure that the concentration of airborne alpha-emitting radionuclides would not be underestimated when glass-fiber filters are used. 32 references, 21 figures, 11 tables.

  8. 10 CFR 20.1203 - Determination of external dose from airborne radioactive material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Determination of external dose from airborne radioactive... RADIATION Occupational Dose Limits § 20.1203 Determination of external dose from airborne radioactive material. Licensees shall, when determining the dose from airborne radioactive material, include...

  9. 10 CFR 20.1203 - Determination of external dose from airborne radioactive material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Determination of external dose from airborne radioactive... RADIATION Occupational Dose Limits § 20.1203 Determination of external dose from airborne radioactive material. Licensees shall, when determining the dose from airborne radioactive material, include...

  10. 10 CFR 20.1203 - Determination of external dose from airborne radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Determination of external dose from airborne radioactive... RADIATION Occupational Dose Limits § 20.1203 Determination of external dose from airborne radioactive material. Licensees shall, when determining the dose from airborne radioactive material, include...

  11. 10 CFR 20.1203 - Determination of external dose from airborne radioactive material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Determination of external dose from airborne radioactive... RADIATION Occupational Dose Limits § 20.1203 Determination of external dose from airborne radioactive material. Licensees shall, when determining the dose from airborne radioactive material, include...

  12. 77 FR 24746 - Constraint on Releases of Airborne Radioactive Materials to the Environment for Licensees Other...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ... COMMISSION Constraint on Releases of Airborne Radioactive Materials to the Environment for Licensees Other..., ``Constraint on Releases of Airborne Radioactive Materials to the Environment for Licensees other than Power... on airborne emissions of radioactive material to the environment. ADDRESSES: Please refer to...

  13. Identification of airborne radioactive spatial patterns in Europe - Feasibility study using Beryllium-7.

    PubMed

    Hernández-Ceballos, M A; Cinelli, G; Tollefsen, T; Marín-Ferrer, M

    2016-05-01

    The present study proposes a methodology to identify spatial patterns in airborne radioactive particles in Europe. The methodology is based on transforming the activity concentrations in the set of stations for each month (monthly index), due to the tightly spaced sampling intervals (daily to monthly), in combination with hierarchical and non-hierarchical clustering approaches, due to the lack of a priori knowledge of the number of clusters to be created. Three different hierarchical cluster methodologies are explored to set the optimal number of clusters necessary to initialize the non-hierarchical one (k-means). To evaluate this methodology, cosmogenic beryllium-7 ((7)Be) data, collected between 2007 and 2010 at 19 sampling stations in European Union (EU) countries and stored in the Radioactivity Environmental Monitoring (REM) database, are used. This methodology yields a solution with three distinguishable clusters (south, central and north), each with a different evolution of the (7)Be monthly index. Clear differences between monthly indices are shown in both intensity and time trends, following a latitudinal distribution of the sampling stations. This cluster result is evaluated performing ANOVA analysis, considering the original (7)Be activity concentrations grouped in each cluster. The statistical results (among clusters and sampling stations within clusters) confirm the spatial distribution of (7)Be in Europe, and, hence, reinforce the use of this methodology. Finally, the impact of tropopause height on this grouping is successfully tested, suggesting its influence on the spatial distribution of (7)Be in Europe. For airborne radioactive particles the analysis gave valuable results that improve knowledge of these atmospheric compounds in Europe. Hence, this work addresses a methodology to a grouping of airborne sampling stations, 1) allowing a better understanding of the distribution of (7)Be activity concentrations in the EU, and 2) serving as a basis for

  14. Electrical charge measurements on fine airborne particles

    SciTech Connect

    Tardos, G.I.; Dietz, P.W.; Snaddon, R.W.L.

    1984-11-01

    A small parallel-plate precipitator and a theoretical collection model have been used to determine the distribution of charges acquired by monodisperse airborne polystyrene latex particles in a corona charger. The mean charge based on the total number of particles was found to be slightly higher than half the predicted saturation charge, and it agreed well with independent measurements made in a Faraday cage particle separator. The importance of careful measurements of particle charge in fine particle transport studies is highlighted by a discussion of the effect of charge (particle mobility) distribution width on observed transport characteristics.

  15. Functional requirements document for measuring emissions of airborne radioactive materials

    SciTech Connect

    Criddle, J.D. Jr.

    1994-09-01

    This document states the functional requirements and procedures for systems making measurements of radioactive airborne emissions from facilities at the Hanford Site. The following issues are addressed in this document: Definition of the program objectives; Selection of the overall approach to collecting the samples; Sampling equipment design; Sampling equipment maintenance, and quality assurance issues. The intent of this document is to assist WHC in demonstrating a high quality of air emission measurements with verified system performance based on documented system design, testing, inspection, and maintenance.

  16. Airborne soil organic particles generated by precipitation

    NASA Astrophysics Data System (ADS)

    Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.; Piens, Dominique S.; China, Swarup; Kovarik, Libor; Keiluweit, Marco; Arey, Bruce W.; Gilles, Mary K.; Laskin, Alexander

    2016-06-01

    Airborne organic particles play a critical role in Earth's climate, public health, air quality, and hydrological and carbon cycles. However, sources and formation mechanisms for semi-solid and solid organic particles are poorly understood and typically neglected in atmospheric models. Laboratory evidence suggests that fine particles can be formed from impaction of mineral surfaces by droplets. Here, we use chemical imaging of particles collected following rain events in the Southern Great Plains, Oklahoma, USA and after experimental irrigation to show that raindrop impaction of soils generates solid organic particles. We find that after rain events, sub-micrometre solid particles, with a chemical composition consistent with soil organic matter, contributed up to 60% of atmospheric particles. Our irrigation experiments indicate that intensive water impaction is sufficient to cause ejection of airborne soil organic particles from the soil surface. Chemical imaging and micro-spectroscopy analysis of particle physico-chemical properties suggest that these particles may have important impacts on cloud formation and efficiently absorb solar radiation. We suggest that raindrop-induced formation of solid organic particles from soils may be a widespread phenomenon in ecosystems such as agricultural systems and grasslands where soils are exposed to strong, episodic precipitation events.

  17. Airborne Nanostructured Particles and Occupational Health

    NASA Astrophysics Data System (ADS)

    Maynard, Andrew D.; Kuempel, Eileen D.

    2005-12-01

    Nanotechnology is leading to the development in many field, of new materials and devices in many fields that demonstrate nanostructure-dependent properties. However, concern has been expressed that these same properties may present unique challenges to addressing potential health impact. Airborne particles associated with engineered nanomaterials are of particular concern, as they can readily enter the body through inhalation. Research into the potential occupational health risks associated with inhaling engineered nanostructured particles is just beginning. However, there is a large body of data on occupational and environmental aerosols, which is applicable to developing an initial assessment of potential risk and risk reduction strategies. Epidemiological and pathological studies of occupational and environmental exposures to airborne particles and fibers provide information on the aerosol-related lung diseases and conditions that have been observed in humans. Toxicological studies provide information on the specific disease mechanisms, dose-response relationships, and the particle characteristics that influence toxicity, including the size, surface area, chemistry or reactivity, solubility, and shape. Potential health risk will depend on the magnitude and nature of exposures to airborne nanostructured particles, and on the release, dispersion, transformation and control of materials in the workplace. Aerosol control methods have not been well-characterized for nanometer diameter particles, although theory and limited experimental data indicate that conventional ventilation, engineering control and filtration approaches should be applicable in many situations. Current information supports the development of preliminary guiding principles on working with engineered nanomaterials. However critical research questions remain to be answered before the potential health risk of airborne nanostructured particles in the workplace can be fully addressed.

  18. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... radioactive material. 50-204.22 Section 50-204.22 Public Contracts and Property Management Other Provisions... FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive material. (a) No employer shall possess, use or transport radioactive material in such a manner as to cause any...

  19. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... radioactive material. 50-204.22 Section 50-204.22 Public Contracts and Property Management Other Provisions... FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive material. (a) No employer shall possess, use or transport radioactive material in such a manner as to cause any...

  20. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... radioactive material. 50-204.22 Section 50-204.22 Public Contracts and Property Management Other Provisions... FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive material. (a) No employer shall possess, use or transport radioactive material in such a manner as to cause any...

  1. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... radioactive material. 50-204.22 Section 50-204.22 Public Contracts and Property Management Other Provisions... FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive material. (a) No employer shall possess, use or transport radioactive material in such a manner as to cause any...

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

    ERIC Educational Resources Information Center

    Mercer, Thomas T., Ed.; And Others

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

  3. Monitoring radioactive plumes by airborne gamma-ray spectrometry

    SciTech Connect

    Grasty, R.L.; Hovgaard, J.; Multala, J.

    1996-06-01

    Airborne gamma-ray spectrometer surveys using large volume sodium-iodide detectors are routinely flown throughout the world for mineral exploration and geological mapping. Techniques have now been developed to detect and map man-made sources of radiation. In Canada, airborne gamma-rays surveys have been flown around nuclear reactors to map {sup 41}Ar plumes from nuclear reactors and to calculate the dose rate at ground level. In May 1986, the Finnish Geological survey aircraft flew through a radioactive plume from the Chernobyl nuclear accident. As the aircraft flew through the plume, the aircraft became increasingly contaminated. By measuring the final aircraft contamination, the activity of the plume could be separated from the contamination due to the aircraft. Within 1 h of encountering the plume, the aircraft activity was comparable to the maximum levels found in the plume. From an analysis of the gamma-ray spectra, the concentration of {sup 131}I and {sup 140}La within the plume were calculated as a function of time.

  4. Airborne radioactive effluent study at the Savannah River Plant

    SciTech Connect

    Blanchard, R.L.; Broadway, J.A.; Sensintaffar, E.L.; Kirk, W.P.; Kahn, B.; Garrett, A.J.

    1984-07-01

    Under the Clean Air Act, Sections 112 and 122 as amended in 1977, the Office of Radiation Programs (OPR) of the United States Environmental Protection Agency is currently developing standards for radionuclides emitted to the air by several source categories. In order to confirm source-term measurements and pathway calculations for radiation exposures to humans offsite, the ORP performs field studies at selected facilities that emit radionuclides. This report describes the field study conducted at the Savannah River Plant (SRP), a laboratory operated by E.I. du Pont de Nemours and Company for the US Department of Energy. This purpose of the study at ARP was to verify reported airborne releases and resulting radiation doses from the facility. Measurements of radionuclide releases for brief periods were compared with measurements performed by SRP staff on split samples and with annual average releases reported by SRP for the same facilities. The dispersion model used by SRP staff to calculate radiation doses offsite was tested by brief environmental radioactivity measurements performed simultaneously with the release measurements, and by examining radioactivity levels in environmental samples. This report describes in detail all measurements made and data collected during the field study and presents the results obtained. 34 references, 18 figures, 49 tables.

  5. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, David G.

    1993-01-01

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  6. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, D.G.

    1993-03-30

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  7. Various consequences regarding hypothetical dispersion of airborne radioactivity in a city center.

    PubMed

    Jonsson, Lage; Plamboeck, Agneta H; Johansson, Erik; Waldenvik, Mattias

    2013-02-01

    In case of dispersion of airborne radioactive material in a city center a number of questions will prompt for an answer. While many questions can get their answers in due course of time based on results of tests and sampling, a good understanding of the quantitative effect of dispersion will be very helpful to rescue staff, in particular in the early stage. In the following dose and dose rate estimates are presented for three scenarios including dispersion of radioactivity in a city center. In one case the activity is released in an open place, in another from a roof and in the third case from a source on a street where the wind is blowing along the street. In each case, at specific positions, estimates are made of dose from inhalation, and dose rates for contamination on skin as well as from radioactive particles deposited onto ground, walls and roofs (external exposure) in the city center. It should be noted that the deposition pattern in urban areas varies greatly which means that the consequences are difficult to predict. The dispersion is influenced by recirculation behind tall buildings and diverted flow close to street-ends, which have significant effects on the deposit pattern. Regarding the relative importance of contributions to total dose it is found that inhalation could play a major role for long term effects while dose to skin might dominate acute effects.

  8. Airborne radioactivity survey in the vicinity of Grants, McKinley and Valencia Counties, New Mexico

    USGS Publications Warehouse

    Stead, Frank W.

    1951-01-01

    An airborne radioactivity survey in the vicinity of Grants, New Mexico, was made on May 28. 1951; aeromagnetic measurements were made concurrently with the radioactivity measurements. Several radioactivity anomalies were noted in conjunction with negative magnetic anomalies; this association is unusual and may reflect a genetic relationship between the uranium mineralization and the geologic structure causing the negative magnetic effect. Further investigation of the vicinity of the anomalies near the Haystack area, including ground magnetometer survey, seems warranted.

  9. Light scattering from nonspherical airborne particles: Experimental and theoretical comparisons

    NASA Astrophysics Data System (ADS)

    Hirst, Edwin; Kaye, Paul H.; Guppy, John R.

    1994-10-01

    Spatial intensity distribution of laser light scattered by airborne hazardous particles such as asbestos fiber is studied to classify particles shape and size. Theoretical treatment is based on Rayleigh-Gans formalism. Theoretical and experimental data are in good agreement.

  10. Airborne radioactivity surveys in the Mojave Desert region, Kern, Riverside, and San Bernardino Counties, California

    USGS Publications Warehouse

    Moxham, Robert M.

    1952-01-01

    Airborne radioactivity surveys in the Mojave Desert region Kern, Riverside, and Bernardino counties were made in five areas recommended as favorable for the occurrence of radioactive raw materials: (1) Rock Corral area, San Bernardino County. (2) Searles Station area, Kern county. (3) Soledad area, Kern County. (4) White Tank area, Riverside and San Bernardino counties. (5) Harvard Hills area, San Bernardino County. Anomalous radiation was detected in all but the Harvard Hills area. The radioactivity anomalies detected in the Rock Corral area are of the greatest amplitude yet recorded by the airborne equipment over natural sources. The activity is apparently attributable to the thorium-beating mineral associated with roof pendants of crystalline metamorphic rocks in a granitic intrusive. In the Searles Station, Soledad, and White Tank area, several radioactivity anomalies of medium amplitude were recorded, suggesting possible local concentrations of radioactive minerals.

  11. Enumerating Spore-Forming Bacteria Airborne with Particles

    NASA Technical Reports Server (NTRS)

    Lin, Ying; Barengoltz, Jack

    2006-01-01

    A laboratory method has been conceived to enable the enumeration of (1) Cultivable bacteria and bacterial spores that are, variously, airborne by themselves or carried by, parts of, or otherwise associated with, other airborne particles; and (2) Spore-forming bacteria among all of the aforementioned cultivable microbes.

  12. Airborne radioactivity survey of the Miller Hill area, Carbon county, Wyoming

    USGS Publications Warehouse

    Meuschke, J.L.; Moxham, R.M.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey covering 65 square miles northwest of Miller Hill, Carbon county, Wyoming. The survey was made by the U.S. Geological Survey as part of a cooperative program with the U.S. Atomic Energy Commission. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomalies shown on the accompanying map cannot be interpreted in terms of either the radioactive content or the extent of the source materials. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to uranium, or to thorium, or to a combination of uranium and thorium. The radioactivity that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the surrounding area. Any particular anomaly

  13. Airborne biological particles and electric fields

    NASA Astrophysics Data System (ADS)

    Benninghoff, William S.; Benninghoff, Anne S.

    1982-01-01

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

  14. Modification of Poisson Distribution in Radioactive Particle Counting.

    ERIC Educational Resources Information Center

    Drotter, Michael T.

    This paper focuses on radioactive practicle counting statistics in laboratory and field applications, intended to aid the Health Physics technician's understanding of the effect of indeterminant errors on radioactive particle counting. It indicates that although the statistical analysis of radioactive disintegration is best described by a Poisson…

  15. Airborne radioactivity survey of parts of Atlantic Ocean beach, Virginia to Florida

    USGS Publications Warehouse

    Moxham, R.M.; Johnson, R.W.

    1953-01-01

    The accompanying maps show the results of an airborne radioactivity survey along the Atlantic Ocean beach from Cape Henry, Virginia to Cape Fear, North Carolina and from Savannah Bach Georgia to Miami Beach, Florida. The survey was made March 23-24, 1953, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a Douglas DC-3 aircraft and consisted of one flight line, at a 500-foot altitude, parallel to the beach. The vertical projection of the flight line coincided approximately with the landward limit of the modern beach. The width of the zone on the ground from which anomalous radiation is measured at the normal 500 foot flight altitude varies with the areal extent radioactivity of the source. For strong sources of radioactivity the width of the zone would be as much as 1,400 feet. The location of the flight lines is shown on the index map below. No abnormal radioactivity was detected along the northern flight line between Cape Henry, Virginia and Cape Fear, North Carolina. Along the southern flight line fourteen areas of abnormal radioactivity were detected between Savannah Beach, Georgia and Anastasia Island, Florida as shown on the map on the left. The abnormal radioactivity is apparently due to radioactive minerals associated with "black sand" deposits with occur locally along the beach in this region. The present technique of airborne radioactivity measurement does not permit distinguishing between activity sue to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. It is not possible to determine the extent or radioactive content of the materials responsible for the abnormal radioactivity. The information given on the accompanying map indicates only those localities of greater-than-average radioactivity and, therefore suggest areas in which uranium and thorium deposits are more

  16. 10 CFR 20.1203 - Determination of external dose from airborne radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Determination of external dose from airborne radioactive material. 20.1203 Section 20.1203 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST... equivalent to an individual should be based upon measurements using instruments or individual...

  17. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false Exposure to airborne radioactive material. 50-204.22 Section 50-204.22 Public Contracts and Property Management Other Provisions Relating to Public Contracts PUBLIC CONTRACTS, DEPARTMENT OF LABOR 204-SAFETY AND HEALTH STANDARDS...

  18. Savannah River Site Ingestion Pathway Methodology Manual for Airborne Radioactive Releases

    SciTech Connect

    Vincent, A.W. III

    2001-01-03

    This manual documents a recommended methodology for determining the ingestion pathway consequences of hypothetical accidental airborne radiological releases from facilities at the Savannah River Site. Both particulate and tritiated radioactive contaminants are addressed. Other approaches should be applied for evaluation of routine releases.

  19. Airborne radioactivity survey of parts of the Atlantic Ocean beach, North and South Carolina

    USGS Publications Warehouse

    Meuschke, J.L.; Moxham, R.M.; Bortner, T.E.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey along the Atlantic Ocean beach between Edisto Island, South Carolina and Cape Fear, North Carolina. The survey was made May 20, 1953, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a Douglas DC-3 aircraft and consisted of one flight line, at a 500-foot altitude, parallel to the beach. The vertical projection of the flight line coincided approximately with the landward limit of the modern beach. The width of the zone on the ground from which anomalous radiation is measured at the nominal 500 foot flight altitude varies with areal extent and intensity of radioactivity of the source. For strong sources of radioactivity the width of the zone may be as much as 1400 feet. The accompanying maps show the approximate locations of the areas of greater-than-average radioactivity (at left) and the location of the traverse flown (at right). The abnormal radioactivity is apparently caused by radioactive minerals associated with "black sand" deposits which occur locally along the beach in this region. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or a combination of these elements. It is not possible to determine the extent or radioactive content of the materials responsible for the abnormal radioactivity. The information given in the accompanying map showing the localities of greater-than-average radioactivity therefore, suggests areas in which uranium and thorium deposits are more likely to occur.

  20. Airborne soil organic particles generated by precipitation

    SciTech Connect

    Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.; Piens, Dominique S.; China, Swarup; Kovarik, Libor; Keiluweit, Marco; Arey, Bruce W.; Gilles, Mary K.; Laskin, Alexander

    2016-05-02

    Airborne organic particles play a critical role in the Earth’s climate1, public health2, air quality3, and hydrological and carbon cycles4. These particles exist in liquid, amorphous semi-solid, or solid (glassy) phase states depending on their composition and ambient conditions5. However, sources and formation mechanisms for semi- solid and solid organic particles are poorly understood and typically neglected in atmospheric models6. Here we report field evidence for airborne solid organic particles generated by a “raindrop” mechanism7 pertinent to atmosphere – land surface interactions (Fig. 1). We find that after rain events at Southern Great Plains, Oklahoma, USA, submicron solid particles, with a composition consistent with soil organic matter, contributed up to 60% of atmospheric particles in number. Subsequent experiments indicate that airborne soil organic particles are ejected from the surface of soils caused by intensive rains or irrigation. Our observations suggest that formation of these particles may be a widespread phenomenon in ecosystems where soils are exposed to strong, episodic precipitation events such as agricultural systems and grasslands8. Chemical imaging and micro-spectroscopy analysis of their physico-chemical properties suggests that airborne soil organic particles may have important impacts on cloud formation and efficiently absorb solar radiation and hence, are an important type of particles.

  1. Airborne radioactivity survey of the Gulf of Mexico beach between Sanibel Island and Caladesi Island, Florida

    USGS Publications Warehouse

    Meuschke, J.L.; Moxham, R.M.; Bortner, T.E.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey along the Gulf of Mexico beach between Sanibel Island and Caladesi Island in Florida. This survey was made May 4, 1953, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a Douglas DC-3 aircraft and consisted of one flight line, at a 500-foot altitude , parallel to the beach. The vertical projection of the flight line coincided approximately with the landward limit of the modern beach. The width of the zone on the ground from which anomalous radiation is measured at the nominal 500 foot flight altitude varies with the areal extent and intensity of the radioactivity the width of the zone may be as much as 1400 feet. The accompanying map and index map show the approximate locations of the areas of greater-than-average radioactivity and the location of the traverse flown. The abnormal radioactivity is apparently caused by radioactive minerals associated with "black sand" deposits which occur locally along the beach in the region. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. It is not possible to determine the extent or radioactive content of the materials responsible for the abnormal radioactivity. The information given in the accompanying map showing the localities of greater-than-average radioactivity therefore, suggests area in which uranium or thorium deposits are more likely to occur.

  2. HUMAN INTERINDIVIDUAL VARIABILITY IN SUSCEPTIBILITY TO AIRBORNE PARTICLES

    EPA Science Inventory

    Part of the explanation for the persistent epidemiological findings of associations between mortality and morbidity with relatively modest ambient exposures to airborne particles may be that some people are much more susceptible to particle-induced responses than others. This stu...

  3. INEL historical dose evaluation: Reconstruction of operational airborne releases of radioactivity to the environment

    SciTech Connect

    Wenzel, D.R.; Peterson, H.K.; Dickson, R.L.

    1993-06-01

    Airborne releases of radioactivity from the operation of reactors and processes at the Idaho National Engineering Laboratory (INEL) since the early 1950s have been reconstructed. Operational releases discussed are those which are continuous and somewhat uniform over a period of time. The primary source of information on operational releases was the measurement of stack effluents as reported in the Radioactive Waste Management Information System (RWMIS) data base and technical reports. The data in the RWMIS data base is generally complete and reliable for releases that occurred since the early 1970s. Data for the 1960s was found to be less detailed and reflected less sophisticated monitoring instrumentation and record keeping systems. Data for the 1950s in general did not identify the specific mixture of radionuclides released. Operational releases of airborne radioactivity from the INEL, particularly in the early years of operation, have been reconstructed using current computer programs with reactor operating and fuel processing knowledge. Techniques used to reconstruct releases of airborne radioactivity to the environment from INEL operational releases and problems encountered are discussed.

  4. Airborne radioactivity of portions of the Defiance Uplift and Carrizo Mountains, Apache county, Arizona

    USGS Publications Warehouse

    Johnson, R.W.; Moxham, R.M.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey covering 940 square miles in Apache county, Arizona. The survey was made by the U.S. Geological Survey from September 8 to October 3, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the

  5. Airborne radioactivity survey of the Devils Tower area, Crook county, Wyoming

    USGS Publications Warehouse

    Henderson, J.R.; Moxham, R.M.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey covering 45 square miles northwest of Devils Tower, Crook County, Wyoming. The survey was made by the U.S. Geological Survey on September 4, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the

  6. Airborne radioactivity survey of the West Lonetree area, Uinta county, Wyoming

    USGS Publications Warehouse

    Meuschke, J.L.; Moxham, R.M.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey in an area of 154 square miles in Uinta county, Wyoming. The survey was made by the U.S. Geological Survey, October 23, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the surrounding area

  7. Airborne radioactivity survey of the Aspen Mountain area, Sweetwater county, Wyoming

    USGS Publications Warehouse

    Meuschke, J.L.; Moxham, R.M.

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey covering 700 square miles in the Aspen Mountain area, Sweetwater county, Wyoming. The survey was made by the U.S. Geological Survey, October 22, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils

  8. Airborne radioactivity survey of the Tabernacle Buttes area, Sublette and Fremont counties, Wyoming

    USGS Publications Warehouse

    1953-01-01

    The accompanying map shows the results of an airborne radioactivity survey in an area of 670 square miles in Sublette and Fremont counties, Wyoming. The survey was made by the U.S. Geological Survey, October 20, 1952, as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation-detection equipment mounted in a Douglas DC-3 aircraft. Parallel traverse lines, spaced at quarter-mile intervals, were flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyro-stabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. At 500 feet above the ground, the width of the zone from which anomalous radioactivity is measured varies with the intensity of radiation of the source and, for strong sources, the width would be as much as 1,400 feet. Quarter-mile spacing of the flight paths of the aircraft should be adequate to detect anomalies from strong sources of radioactivity. However, small areas of considerable radioactivity midway between flight paths may not be noted. The approximate location of each radioactivity anomaly is shown on the accompanying map. The plotted position of an anomaly may be in error by as much as a quarter of a mile owing to errors in the available base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The radioactivity anomaly that is recorded by airborne measurements at 500 feet above the ground can be caused by: 1. A moderately large area in which the rocks and soils are slightly more radioactive than the rocks and soils of the surrounding area. 2. A smaller area in which the rocks and soils are considerably more radioactive than rocks and soils in the surrounding area. 3. A very small area in which to rocks and soils are much more radioactive than the rocks and soils of the

  9. Digital Holographic Interferometry for Airborne Particle Characterization

    DTIC Science & Technology

    2015-03-19

    hologram and its extinction cross section, and a computational demonstration that holographic interferometry can resolve aerosol particle size ...holographic interferometry can resolve aerosol particle size evolution. (a) Papers published in peer-reviewed journals (N/A for none) Enter List of...Characterization of Atmospheric Aerosols workshop, Smolenice, Slovak Republic (2013). 7. Poster : Digital Holographic Imaging of Aerosol Particles In-Flight

  10. Enhanced airborne radioactivity during a pine pollen release episode.

    PubMed

    Tschiersch, J; Frank, G; Roth, P; Wagenpfeil, F; Watterson, F; Watterson, J

    1999-07-01

    A single episode of pine pollen release in the highly contaminated area of Novozybkov, Russian Federation, which led to enhanced atmospheric concentrations of 137Cs is discussed. The pollen grains were sampled by a rotating arm impactor and analysed by gamma-spectrometry for 137Cs activity and by image analysis for their size. In the vicinity of a forest, a maximum concentration of 4.5+/-0.4 mBq m(-3) was measured, and a mean activity per pollen grain of 260+/-80 nBq was determined. The emission rate of the Novozybkov mixed pine forest was estimated to be approximately 400 Bq m(-2) per year. Because of the large size of pine pollen grains (about 50 microm) and the short emission period of 5-8 days per year, the estimated potential annual inhalation doses are very low. Biological emissions including pollen release may be a source of increased airborne radionuclide concentrations at larger distances from the source areas as well.

  11. Airborne soil organic particles generated by precipitation

    SciTech Connect

    Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.; Piens, Dominique S.; China, Swarup; Kovarik, Libor; Keiluweit, Marco; Arey, Bruce W.; Gilles, Mary K.; Laskin, Alexander

    2016-05-02

    Airborne organic particles play a critical role in Earth’s climate1, public health2, air quality3, and hydrological and carbon cycles4. However, sources and formation mechanisms for semi-solid and solid organic particles5 are poorly understood and typically neglected in atmospheric models6. Laboratory evidence suggests that fine particles can be formed from impaction of mineral surfaces by droplets7. Here, we use chemical imaging of particles collected following rain events in the Southern Great Plains, Oklahoma, USA and after experimental irrigation to show that raindrop impaction of soils generates solid organic particles. We find that after rain events, sub-micrometre solid particles, with a chemical composition consistent with soil organic matter, contributed up to 60% of atmospheric particles. Our irrigation experiments indicate that intensive water impaction is sufficient to cause ejection of airborne soil organic particles from the soil surface. Chemical imaging and micro-spectroscopy analysis of particle physico-chemical properties suggest that these particles may have important impacts on cloud formation and efficiently absorb solar radiation. Lastly, we suggest that raindrop-induced formation of solid organic particles from soils may be a widespread phenomenon in ecosystems such as agricultural systems and grasslands where soils are exposed to strong, episodic precipitation events8.

  12. Airborne soil organic particles generated by precipitation

    DOE PAGES

    Wang, Bingbing; Harder, Tristan H.; Kelly, Stephen T.; ...

    2016-05-02

    Airborne organic particles play a critical role in Earth’s climate1, public health2, air quality3, and hydrological and carbon cycles4. However, sources and formation mechanisms for semi-solid and solid organic particles5 are poorly understood and typically neglected in atmospheric models6. Laboratory evidence suggests that fine particles can be formed from impaction of mineral surfaces by droplets7. Here, we use chemical imaging of particles collected following rain events in the Southern Great Plains, Oklahoma, USA and after experimental irrigation to show that raindrop impaction of soils generates solid organic particles. We find that after rain events, sub-micrometre solid particles, with a chemicalmore » composition consistent with soil organic matter, contributed up to 60% of atmospheric particles. Our irrigation experiments indicate that intensive water impaction is sufficient to cause ejection of airborne soil organic particles from the soil surface. Chemical imaging and micro-spectroscopy analysis of particle physico-chemical properties suggest that these particles may have important impacts on cloud formation and efficiently absorb solar radiation. Lastly, we suggest that raindrop-induced formation of solid organic particles from soils may be a widespread phenomenon in ecosystems such as agricultural systems and grasslands where soils are exposed to strong, episodic precipitation events8.« less

  13. Airborne particle exposure and extrinsic skin aging.

    PubMed

    Vierkötter, Andrea; Schikowski, Tamara; Ranft, Ulrich; Sugiri, Dorothea; Matsui, Mary; Krämer, Ursula; Krutmann, Jean

    2010-12-01

    For decades, extrinsic skin aging has been known to result from chronic exposure to solar radiation and, more recently, to tobacco smoke. In this study, we have assessed the influence of air pollution on skin aging in 400 Caucasian women aged 70-80 years. Skin aging was clinically assessed by means of SCINEXA (score of intrinsic and extrinsic skin aging), a validated skin aging score. Traffic-related exposure at the place of residence was determined by traffic particle emissions and by estimation of soot in fine dust. Exposure to background particle concentration was determined by measurements of ambient particles at fixed monitoring sites. The impact of air pollution on skin aging was analyzed by linear and logistic regression and adjusted for potential confounding variables. Air pollution exposure was significantly correlated to extrinsic skin aging signs, in particular to pigment spots and less pronounced to wrinkles. An increase in soot (per 0.5 × 10(-5) per m) and particles from traffic (per 475  kg per year and square km) was associated with 20% more pigment spots on forehead and cheeks. Background particle pollution, which was measured in low residential areas of the cities without busy traffic and therefore is not directly attributable to traffic but rather to other sources of particles, was also positively correlated to pigment spots on face. These results indicate that particle pollution might influence skin aging as well.

  14. Acoustic Resonator Optimisation for Airborne Particle Manipulation

    NASA Astrophysics Data System (ADS)

    Devendran, Citsabehsan; Billson, Duncan R.; Hutchins, David A.; Alan, Tuncay; Neild, Adrian

    Advances in micro-electromechanical systems (MEMS) technology and biomedical research necessitate micro-machined manipulators to capture, handle and position delicate micron-sized particles. To this end, a parallel plate acoustic resonator system has been investigated for the purposes of manipulation and entrapment of micron sized particles in air. Numerical and finite element modelling was performed to optimise the design of the layered acoustic resonator. To obtain an optimised resonator design, careful considerations of the effect of thickness and material properties are required. Furthermore, the effect of acoustic attenuation which is dependent on frequency is also considered within this study, leading to an optimum operational frequency range. Finally, experimental results demonstrated good particle levitation and capture of various particle properties and sizes ranging to as small as 14.8 μm.

  15. AIRBORNE PARTICLE SIZES AND SOURCES FOUND IN INDOOR AIR

    EPA Science Inventory

    The paper summarizes results of a literature search into the sources, sizes, and concentrations of particles in indoor air, including the various types: plant, animal, mineral, combustion, home/personal care, and radioactive aerosols. This information, presented in a summary figu...

  16. Current concepts on airborne particles and health

    SciTech Connect

    Mauderly, J.L.

    1994-11-01

    Epidemiological evidence of associations between environmental particulate concentrations and both acute and chronic health effects has grown with numerous recent studies conducted in the US and other countries. An association between short-term changes in particulate levels and acute mortality now seems certain. The association is consistent among studies and coherent among indicators of mortality and morbidity. Effects observed at surprisingly low pollution levels have raised concern for current exposures even in modestly polluted cities. Toxicology did not predict the acute mortality effect, and causal mechanisms are difficult to rationalize. Present data suggest that the fine fraction of particulate pollution is more toxic than larger particles, but the contribution of specific particulate species is poorly understood.

  17. Experience of monitoring beaches for radioactive particles.

    PubMed

    Davies, Mike; McCulloch, George; Adsley, Ian

    2007-09-01

    This paper discusses some of the theoretical and practical problems that are encountered in monitoring beaches for hot particles. The experience is from operating a near-continuous monitoring program, for a period of eight years, on beaches near the Dounreay site. The reliability and failure mechanisms of the monitoring systems used will be discussed, together with remedial actions employed. The viability and performance of several types and configurations of radiation detectors will be described, along with methods by which particles might be detected, given their response to buried particles. When large areas are being monitored at high spatial resolution, which is required for efficient particle detection, the volume of data recorded for audit purposes can be very large. The use and abuse of Geographical Information Systems for this work is described. Other practical aspects of performing surveys are also discussed, including understanding health-and-safety requirements; constraints imposed by weather, tides and tidal speed; the logistics of making vehicles available to perform the work; and how a particle should be recovered once detected.

  18. New Methods for Personal Exposure Monitoring for Airborne Particles

    PubMed Central

    Koehler, Kirsten A.; Peters, Thomas

    2016-01-01

    Airborne particles have been associated with a range of adverse cardiopulmonary outcomes, which has driven its monitoring at stationary, central sites throughout the world. Individual exposures, however, can differ substantially from concentrations measured at central sites due to spatial variability across a region and sources unique to the individual, such as cooking or cleaning in homes, traffic emissions during commutes, and widely varying sources encountered at work. Personal monitoring with small, battery-powered instruments enables the measurement of an individual’s exposure as they go about their daily activities. Personal monitoring can substantially reduce exposure misclassification and improve the power to detect relationships between particulate pollution and adverse health outcomes. By partitioning exposures to known locations and sources, it may be possible to account for variable toxicity of different sources. This review outlines recent advances in the field of personal exposure assessment for particulate pollution. Advances in battery technology have improved the feasibility of 24-hour monitoring, providing the ability to more completely attribute exposures to microenvironment (e.g., work, home, commute). New metrics to evaluate the relationship between particulate matter and health are also being considered, including particle number concentration, particle composition measures, and particle oxidative load. Such metrics provide opportunities to develop more precise associations between airborne particles and health and may provide opportunities for more effective regulations. PMID:26385477

  19. Flow analysis of airborne particles in a hospital operating room

    NASA Astrophysics Data System (ADS)

    Faeghi, Shiva; Lennerts, Kunibert

    2016-06-01

    Preventing airborne infections during a surgery has been always an important issue to deliver effective and high quality medical care to the patient. One of the important sources of infection is particles that are distributed through airborne routes. Factors influencing infection rates caused by airborne particles, among others, are efficient ventilation and the arrangement of surgical facilities inside the operating room. The paper studies the ventilation airflow pattern in an operating room in a hospital located in Tehran, Iran, and seeks to find the efficient configurations with respect to the ventilation system and layout of facilities. This study uses computational fluid dynamics (CFD) and investigates the effects of different inflow velocities for inlets, two pressurization scenarios (equal and excess pressure) and two arrangements of surgical facilities in room while the door is completely open. The results show that system does not perform adequately when the door is open in the operating room under the current conditions, and excess pressure adjustments should be employed to achieve efficient results. The findings of this research can be discussed in the context of design and controlling of the ventilation facilities of operating rooms.

  20. Airborne measurements of gases and particles from an Alaskan wildfire

    NASA Astrophysics Data System (ADS)

    Nance, J. D.; Hobbs, Peter V.; Radke, Lawrence F.; Ward, Darold E.

    1993-08-01

    Airborne measurements of several gaseous and particulate chemical species were obtained in the emissions from a wildfire that burned in an old black spruce forest in Alaska during the summer of 1990. The relative proportions of most of the measured plume constituents are consistent with ground-based and airborne measurements in the plumes of several other biomass fires, and with laboratory measurements. Possible exceptions include the mean fine-particle emission factor, which was about 3 times larger than predicted from a regression relation based on measurements of the smoke from several prescribed biomass fires, and the mean CH4/CO molar emission ratio which was at the low end of a range of values measured for other biomass fires. Measurements of water-soluble particulate ions in the smoke plume from the Alaskan wildfire indicate that acids formed from the oxides of sulphur and nitrogen were partially neutralized inside cloud droplets by NH3 absorbed from the plume.

  1. Evaluating airborne and ground based gamma spectrometry methods for detecting particulate radioactivity in the environment: a case study of Irish Sea beaches.

    PubMed

    Cresswell, A J; Sanderson, D C W

    2012-10-15

    In several places, programmes are in place to locate and recover radioactive particles that have the potential to cause detrimental health effects in any member of the public who may encounter them. A model has been developed to evaluate the use of mobile gamma spectrometry systems within such programmes, with particular emphasis on large volume (16l) NaI(Tl) detectors mounted in low flying helicopters. This model uses a validated Monte Carlo code with assessment of local geochemistry and natural and anthropogenic background radiation concentrations and distributions. The results of the model, applied to the example of particles recovered from beaches in the vicinity of Sellafield, clearly show the ability of rapid airborne surveys conducted at 75 m ground clearance and 120 kph speeds to demonstrate the absence of sources greater than 5 MBq (137)Cs within large areas (10-20 km(2)h(-1)), and identify areas requiring further ground based investigation. Lowering ground clearance for airborne surveys to 15m whilst maintaining speeds covering 1-2 km(2) h(-1) can detect buried (137)Cs sources of 0.5MBq or greater activity. A survey design to detect 100 kBq (137)Cs sources at 10 cm depth has also been defined, requiring surveys at <15m ground clearance and <2 ms(-1) ground speed. The response of airborne systems to the Sellafield particles recovered to date has also been simulated, and the proportion of the existing radiocaesium background in the vicinity of the nuclear site has been established. Finally the rates of area coverage and sensitivities of both airborne and ground based approaches are compared, demonstrating the ability of airborne systems to increase the rate of particle recovery in a cost effective manner. The potential for equipment and methodological developments to improve performance are discussed.

  2. A system for aerodynamically sizing ultrafine environmental radioactive particles

    SciTech Connect

    Olawoyin, L.

    1995-09-01

    The unattached environmental radioactive particles/clusters, produced mainly by {sup 222}Rn in indoor air, are usually few nanometers in size. The inhalation of these radioactive clusters can lead to deposition of radioactivity on the mucosal surface of the tracheobronchial tree. The ultimate size of the cluster together with the flow characteristics will determine the depositional site in the human lung and thus, the extent of damage that can be caused. Thus, there exists the need for the determination of the size of the radioactive clusters. However, the existing particle measuring device have low resolution in the sub-nanometer range. In this research, a system for the alternative detection and measurement of the size of particles/cluster in the less than 2 nm range have been developed. The system is a one stage impactor which has a solid state spectrometer as its impaction plate. It`s major feature is the nozzle-to-plate separation, L. The particle size collected changes with L and thus, particle size spectroscopy is achieved by varying L. The number of collected particles is determined by alpha spectroscopy. The size-discriminating ability of the system was tested with laboratory generated radon particles and it was subsequently used to characterize the physical (size) changes associated with the interaction of radon progeny with water vapor and short chain alcohols in various support gases. The theory of both traditional and high velocity jet impactors together with the design and evaluation of the system developed in this study are discussed in various chapters of this dissertation. The major results obtained in the course of the study are also presented.

  3. Anthropogenic Osmium in Airborne Particles from Woods Hole, Massachusetts, USA

    NASA Astrophysics Data System (ADS)

    Peucker-Ehrenbrink, B.; Sen, I. S.; Geboy, N.

    2012-12-01

    The global geochemical cycle of osmium has been significantly disturbed by the introduction of automobile exhaust catalysts to convert noxious gas emissions into more benign forms. Anthropogenic osmium has been reported in rainwater, snow, and in the urban airborne particles from around the world to reveal global-scale osmium pollution [1, 2]. In this study, we report on the platinum group element (PGE) concentrations and osmium isotope ratios of airborne particles (PM10) collected in Woods Hole, a small coastal town in Massachusetts to better understand inputs of anthropogenic osmium to rural environments. We further investigate the use of osmium isotopes to track sources of airborne particles and support source apportionment studies on a continental scale. The samples used in this study were collected at Woods Hole Oceanographic Institution over one year (2008-2009). From this collection twelve samples for which the backward air mass trajectories have been determined were selected for osmium isotope analyses. Our results show that the osmium and platinum concentrations are an order of magnitude lower when compared to downtown Boston [2]. The average Os, Pt and Ir concentrations are 0.006±0.012, 0.019±0.023, and 0.685±0.634 pg m-3, respectively. The 187Os/188Os of the aerosols range from 0.275 to 0.788. As continental crust is radiogenic (187Os/188Os >1) and PGE ore bodies generally have unradiogenic 187Os/188Os (~0.2), the unradiogenic 187Os/188Os signature of the aerosols indicates anthropogenic contributions. With 95% of the total osmium mobilization on land being attributed to human activities [3], it is clear that human imprint on airborne particles is not restricted to urban centers with high traffic flows, but also affects rural environments. Aerosol particles that have backward air mass trajectories from the Southwest, the densely populated and industrialized Eastern seaboard, are characterized by unradiogenic osmium, while air masses from the North

  4. Airborne Particle Size Distribution Measurements at USDOE Fernald

    SciTech Connect

    Harley, N.H.; Chittaporn, P.; Heikkinen, M.; Medora, R.; Merrill, R.

    2003-03-27

    There are no long term measurements of the particle size distribution and concentration of airborne radionuclides at any USDOE facility except Fernald. Yet the determinant of lung dose is the particle size, determining the airway and lower lung deposition. Beginning in 2000, continuous (6 to 8 weeks) measurements of the aerosol particle size distribution have been made with a miniature sampler developed under EMSP. Radon gas decays to a chain of four short lived solid radionuclides that attach immediately to the resident atmospheric aerosol. These in turn decay to long lived polonium 210. Alpha emitting polonium is a tracer for any atmospheric aerosol. Six samplers at Fernald and four at QC sites in New Jersey show a difference in both polonium concentration and size distribution with the winter measurements being higher/larger than summer by almost a factor of two at all locations. EMSP USDOE Contract DE FG07 97ER62522.

  5. 75 FR 36445 - Draft Regulatory Guide, DG-4018, “Constraint on Releases of Airborne Radioactive Materials To the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ... Environment for Licensees Other Than Power Reactors,'' Proposed Revision 1 of Regulatory Guide 4.20; Draft... of Airborne Radioactive Materials to the Environment for Licensees Other than Power Reactors.'' This... Materials to the Environment for Licensees Other than Power Reactors,'' is available electronically...

  6. GEANT4 calibration of gamma spectrometry efficiency for measurements of airborne radioactivity on filter paper.

    PubMed

    Alrefae, Tareq

    2014-11-01

    A simple method of efficiency calibration for gamma spectrometry was performed. This method, which focused on measuring airborne radioactivity collected on filter paper, was based on Monte Carlo simulations using the toolkit GEANT4. Experimentally, the efficiency values of an HPGe detector were calculated for a multi-gamma disk source. These efficiency values were compared to their counterparts produced by a computer code that simulated experimental conditions. Such comparison revealed biases of 24, 10, 1, 3, 7, and 3% for the radionuclides (photon energies in keV) of Ce (166), Sn (392), Cs (662), Co (1,173), Co (1,333), and Y (1,836), respectively. The output of the simulation code was in acceptable agreement with the experimental findings, thus validating the proposed method.

  7. Quality Assurance Project Plan for radioactive airborne emissions data compilation and reporting

    SciTech Connect

    Burris, S.A.; Thomas, S.P.

    1994-02-01

    This Quality Assurance Project Plan addresses the quality assurance requirements for compiling data from radioactie aiborne emissions. These data will be reported to the US Environmental Protection Agency, the US Department of Energy, and the Washington State Department of Health. Hanford Site radioactive airborne emissions are reported to the US Environmental Protection Agency in compliance with Title 40, Protection of the Environment, Code of Federal Regulations, Part 61, ``National Emissions Standards for Hazardous Air Pollutants , ``Subpart H, ``National Emissions Standards for Emissions of Radionuclides Other Than Radon From Department of Energy Facilities`` (EPA 1989a). Reporting to US Department of Energy is performed in compliance with requirements of US Department of Energy Order 5400.1, General Environmental Protection Program (DOE 1988a).

  8. Dry deposition of large, airborne particles onto a surrogate surface

    NASA Astrophysics Data System (ADS)

    Kim, Eugene; Kalman, David; Larson, Timothy

    Simultaneous measurements of particle dry deposition flux and airborne number concentration in the open atmosphere were made using three different types of artificially generated particles in the size range 10-100 μm - perlite, diatomaceous earth and glass beads. A combination of gravimetric analysis, automated microscopy and sonic anemometry provided size-resolved estimates of both the inertial and gravitational components of the quasi-laminar layer particle deposition velocity, ( Vd) b, as a function of size. Eddy inertial deposition efficiency ( ηdI) was determined as a function of dimensionless eddy Stokes number (Stk e). In the range 3particles and gases to environmental surfaces. DOE Report PNL-SA-6721, Pacific Northwest Laboratories, Richland, WA), used in several regulatory models, significantly under-predicted (up to seven times) ( Vd) b for large particles ( da>10 μm).

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

    PubMed

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

    2009-02-01

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

  10. ESEM-EDX characterisation of airborne particles from an industrialised area of northern Greece.

    PubMed

    Iordanidis, Andreas; Buckman, Jim; Triantafyllou, Athanasios G; Asvesta, Argyro

    2008-10-01

    The aim of this study was to characterise individual airborne particles collected from the Ptolemais-Kozani region (Western Macedonia), northern Greece. Throughout a 1-year period (March 2003 to February 2004), we collected several filters that captured airborne particles at seven sampling sites distributed throughout the area. The airborne particles captured on the filters were then characterised by environmental scanning electron microscopy (ESEM) coupled with energy-dispersive X-ray analysis (EDX). The particles were categorised as geogenic, biogenic and anthropogenic. The main anthropogenic airborne particles were fly ash (released from lignite-fired power plants) and carbonaceous (soot and char) and metalliferous (mainly iron- and copper-enriched) particulates. We present here characteristic ESEM and EDX spectra for the airborne particles and underline the presence of characteristic primary and secondary sulphates.

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

    NASA Astrophysics Data System (ADS)

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

    2013-03-01

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

  12. CHARACTERIZING THE SOURCES OF HUMAN EXPOSURE TO MUTAGENIC AND CARCINOGENIC CHEMICALS IN AIRBORNE FINE PARTICLES

    EPA Science Inventory

    Personal and ambient exposures to airborne fine particles, polycyclic aromatic hydrocarbons (PAH), and genotoxic activity has been studied in populations in the US, Japan, China, and the Czech Republic. Personal exposure monitors used to collect fine particles were extracted f...

  13. Airborne radioactivity survey of parts of Baggs SW and Baggs SE quadrangles, Carbon and Sweetwater counties, Wyoming

    USGS Publications Warehouse

    Henderson, J.R.

    1954-01-01

    The accompanying map shows the results of an airborne radioactivity survey in 151 square miles of Baggs SW and Baggs SE quadrangles, Wyoming. This area is part of a larger survey made in southern Carbon and Sweetwater counties by the U.S. Geological Survey, November 9-24, 1953. The work was undertaken as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a C-47 aircraft and consisted of parallel east-west flight lines spaced at quarter mile intervals, flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyrostabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. The width of the zone on the ground form which the anomalous radiation is measured at the nominal 500 foot flight altitude varied with the areal extent and the intensity of radioactivity of the source. For strong sources of radioactivity the width of the zone may be as much as 1,400 feet. Thus, quarter mile spacing of the flight lines would be adequate to detect anomalies from strong sources of radioactivity; however, small areas of considerable radioactivity midway between flight lines may not be noted. The approximate locations of twelve radioactivity anomalies are shown on the accompanying map. The plotted position of the anomalies may be in error by as much as a quarter mile owing to the errors in available base maps or to the existence of areas on the base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. The radioactivity

  14. Airborne radioactivity survey of parts of Sand Creek SW and Sand Creek SE quadrangles, Sweetwater county, Wyoming

    USGS Publications Warehouse

    Henderson, J.R.

    1954-01-01

    The accompanying map shows the results of an airborne radioactivity survey in 125 square miles of Sand Creek SW and Sand Creek SE quadrangles, Wyoming. This area is part of a larger survey made in southern Carbon and Sweetwater counties by the U.S. Geological Survey, November 9-24, 1953. The work was undertaken as part of a cooperative program with the U.S. Atomic Energy Commission. The survey was made with scintillation detection equipment mounted in a C-47 aircraft and consisted of parallel east-west flight lines spaced at quarter mile intervals, flown approximately 500 feet above the ground. Aerial photographs were used for pilot guidance, and the flight path of the aircraft was recorded by a gyrostabilized, continuous-strip-film camera. The distance of the aircraft from the ground was measured with a continuously recording radio altimeter. The width of the zone on the ground form which the anomalous radiation is measured at the nominal 500 foot flight altitude varied with the areal extent and the intensity of radioactivity of the source. For strong sources of radioactivity the width of the zone may be as much as 1,400 feet. Thus, quarter mile spacing of the flight lines would be adequate to detect anomalies from strong sources of radioactivity; however, small areas of considerable radioactivity midway between flight lines may not be noted. The approximate locations of nine radioactivity anomalies are shown on the accompanying map. The plotted position of the anomalies may be in error by as much as a quarter mile owing to the errors in available base maps or to the existence of areas on the base maps up to several square miles in which it is impossible to find and plot recognizable landmarks. The present technique of airborne radioactivity measurement does not permit distinguishing between activity due to thorium and that due to uranium. An anomaly, therefore, may represent radioactivity due entirely to one or to a combination of these elements. The

  15. Enhanced removal of radioactive particles by fluorocarbon surfactant solutions

    SciTech Connect

    Kaiser, R.; Harling, O.K.

    1993-08-01

    The proposed research addressed the application of ESI`s particle removal process to the non-destructive decontamination of nuclear equipment. The cleaning medium used in this process is a solution of a high molecular weight fluorocarbon surfactant in an inert perfluorinated liquid which results in enhanced particle removal. The perfluorinated liquids of interest, which are recycled in the process, are nontoxic, nonflammable, and environmentally compatible, and do not present a hazard to the ozone layer. The information obtained in the Phase 1 program indicated that the proposed ESI process is technically effective and economically attractive. The fluorocarbon surfactant solutions used as working media in the ESI process survived exposure of up to 10 Mrad doses of gamma rays, and are considered sufficiently radiation resistant for the proposed process. Ultrasonic cleaning in perfluorinated surfactant solutions was found to be an effective method of removing radioactive iron (Fe 59) oxide particles from contaminated test pieces. Radioactive particles suspended in the process liquids could be quantitatively removed by filtration through a 0.1 um membrane filter. Projected economics indicate a pre-tax pay back time of 1 month for a commercial scale system.

  16. Iridium enrichment in airborne particles from kilauea volcano: january 1983.

    PubMed

    Zoller, W H; Parrington, J R; Kotra, J M

    1983-12-09

    Airborne particulate matter from the January 1983 eruption of Kilauea volcano was inadvertently collected on air filters at Mauna Loa Observatory at a sampling station used to observe particles in global circulation. Analyses of affected samples revealed unusually large concentrations of selenium, arsenic, indium, gold, and sulfur, as expected for volcanic emissions. Strikingly large concentrations of iridium were also observed, the ratio of iridium to aluminum being 17,000 times its value in Hawaiian basalt. Since iridium enrichments have not previously been observed in volcanic emissions, the results for Kilauea suggest that it is part of an unusual volcanic system which may be fed by magma from the mantle. The iridium enrichment appears to be linked with the high fluorine content of the volcanic gases, which suggests that the iridium is released as a volatile IrF(6).

  17. Induced radioactivity in and around high-energy particle accelerators.

    PubMed

    Vincke, Helmut; Theis, Chris; Roesler, Stefan

    2011-07-01

    Particle accelerators and their surroundings are locations of residual radioactivity production that is induced by the interaction of high-energy particles with matter. This paper gives an overview of the principles of activation caused at proton accelerators, which are the main machines operated at Conseil Européen pour la Recherche Nucléaire. It describes the parameters defining radio-nuclide production caused by beam losses. The second part of the paper concentrates on the analytic calculation of activation and the Monte Carlo approach as it is implemented in the FLUKA code. Techniques used to obtain, on the one hand, estimates of radioactivity in Becquerel and, on the other hand, residual dose rates caused by the activated material are discussed. The last part of the paper focuses on experiments that allow for benchmarking FLUKA activation calculations and on simulations used to predict activation in and around high-energy proton machines. In that respect, the paper addresses the residual dose rate that will be induced by proton-proton collisions at an energy of two times 7 TeV in and around the Compact Muon Solenoid (CMS) detector. Besides activation of solid materials, the air activation expected in the CMS cavern caused by this beam operation is also discussed.

  18. Influence of radioactivity on surface charging and aggregation kinetics of particles in the atmosphere.

    PubMed

    Kim, Yong-Ha; Yiacoumi, Sotira; Lee, Ida; McFarlane, Joanna; Tsouris, Costas

    2014-01-01

    Radioactivity can influence surface interactions, but its effects on particle aggregation kinetics have not been included in transport modeling of radioactive particles. In this research, experimental and theoretical studies have been performed to investigate the influence of radioactivity on surface charging and aggregation kinetics of radioactive particles in the atmosphere. Radioactivity-induced charging mechanisms have been investigated at the microscopic level, and heterogeneous surface potential caused by radioactivity is reported. The radioactivity-induced surface charging is highly influenced by several parameters, such as rate and type of radioactive decay. A population balance model, including interparticle forces, has been employed to study the effects of radioactivity on particle aggregation kinetics in air. It has been found that radioactivity can hinder aggregation of particles because of similar surface charging caused by the decay process. Experimental and theoretical studies provide useful insights into the understanding of transport characteristics of radioactive particles emitted from severe nuclear events, such as the recent accident of Fukushima or deliberate explosions of radiological devices.

  19. Optimization of detector positioning in the radioactive particle tracking technique.

    PubMed

    Dubé, Olivier; Dubé, David; Chaouki, Jamal; Bertrand, François

    2014-07-01

    The radioactive particle tracking (RPT) technique is a non-intrusive experimental velocimetry and tomography technique extensively applied to the study of hydrodynamics in a great variety of systems. In this technique, arrays of scintillation detector are used to track the motion of a single radioactive tracer particle emitting isotropic γ-rays. This work describes and applies an optimization strategy developed to find an optimal set of positions for the scintillation detectors used in the RPT technique. This strategy employs the overall resolution of the detectors as the objective function and a mesh adaptive direct search (MADS) algorithm to solve the optimization problem. More precisely, NOMAD, a C++ implementation of the MADS algorithm is used. First, the optimization strategy is validated using simple cases with known optimal detector configurations. Next, it is applied to a three-dimensional axisymmetric system (i.e. a vertical cylinder, which could represent a fluidized bed, bubble column, riser or else). The results obtained using the optimization strategy are in agreement with what was previously recommended by Roy et al. (2002) for a similar system. Finally, the optimization strategy is used for a system consisting of a partially filled cylindrical tumbler. The application of insights gained by the optimization strategy is shown to lead to a significant reduction in the error made when reconstructing the position of a tracer particle. The results of this work show that the optimization strategy developed is sensitive to both the type of objective function used and the experimental conditions. The limitations and drawbacks of the optimization strategy are also discussed.

  20. The effect on cast post dimensions of casting investment and airborne particle abrasion.

    PubMed

    Hashem, Danya; German, Matthew J; Wassell, Robert W

    2011-09-01

    Cast posts can sometimes prove difficult to seat fully during fitting. This study compared two different liquid/water dilutions for phosphate bonded investment and the effect of controlled airborne particle abrasion on resulting post diameter. After measuring polymeric post patterns (n = 18), 3 groups were invested using concentrated solution and 3 groups using dilute solution. After casting they were weighed and remeasured then exposed to airborne particle abrasion. Both solutions produced oversized cast posts. Mean diameter reduction during airborne particle abrasion was 8 microm/10s taking an average of 41s to reach precast size. Where a post pattern fits tightly, airborne particle abrasion for 70s should reduce the casting sufficiently to accommodate the cement lute.

  1. Latex allergens in tire dust and airborne particles.

    PubMed Central

    Miguel, A G; Cass, G R; Weiss, J; Glovsky, M M

    1996-01-01

    The prevalence and severity of latex allergy has increased dramatically in the last 15 years due to exposure to natural rubber products. Although historically this health risk has been elevated in hospital personnel and patients, a recent survey has indicated a significant potential risk for the general population. To obtain a wide-spread source for latex exposure, we have considered tire debris. We have searched for the presence of latex allergens in passenger car and truck tire tread, in debris deposited from the atmosphere near a freeway, and in airborne particulate matter samples representative of the entire year 1993 at two sites in the Los Angeles basin (California). After extraction of the samples with phosphate buffered saline, a modified-ELISA inhibition assay was used to measure relative allergen potency and Western blot analyses were used to identify latex allergens. The inhibition studies with the human IgE latex assay revealed inhibition by the tire tread source samples and ambient freeway dust, as well as by control latex sap and latex glove extracts. Levels of extractable latex allergen per unit of protein extracted were about two orders of magnitude lower for tire tread as compared to latex gloves. Western blot analyses using binding of human IgE from latex-sensitive patients showed a band at 34-36 kDa in all tire and ambient samples. Long Beach and Los Angeles, California, air samples showed four additional bands between 50 and 135 kDa. Alternative Western blot analyses using rabbit IgG raised against latex proteins showed a broad band at 30-50 kDa in all samples, with additional bands in the urban air samples similar to the IgE results. A latex cross-reactive material was identified in mountain cedar. In conclusion, the latex allergens or latex cross-reactive material present in sedimented and airborne particulate material, derived from tire debris, and generated by heavy urban vehicle traffic could be important factors in producing latex allergy

  2. Evaluation of Airborne Particle Emissions from Commercial Products Containing Carbon Nanotubes

    PubMed Central

    Huang, Guannan; Park, Jae Hong; Cena, Lorenzo G.; Shelton, Betsy L.; Peters, Thomas M.

    2012-01-01

    The emission of the airborne particles from epoxy resin test sticks with different CNT loadings and two commercial products were characterized while sanding with three grit sizes and three disc sander speeds. The total number concentrations, respirable mass concentrations, and particle size number/mass distributions of the emitted particles were measured using a condensation particle counter, an optical particle counter, and a scanning mobility particle sizer. The emitted particles were sampled on a polycarbonate filter and analyzed using electron microscopy. The highest number concentrations (arithmetic mean = 4670 particles/cm3) were produced with coarse sandpaper, 2% (by weight) CNT test sticks and medium disc sander speed, whereas the lowest number concentrations (arithmetic mean = 92 particles/cm3) were produced with medium sandpaper, 2% CNT test sticks and slow disc sander speed. Respirable mass concentrations were highest (arithmetic mean = 1.01 mg/m3) for fine sandpaper, 2% CNT test sticks and medium disc sander speed and lowest (arithmetic mean = 0.20 mg/m3) for medium sandpaper, 0% CNT test sticks and medium disc sander speed. For CNT-epoxy samples, airborne particles were primarily micrometer-sized epoxy cores with CNT protrusions. No free CNTs were observed in airborne samples, except for tests conducted with 4% CNT epoxy. The number concentration, mass concentration, and size distribution of airborne particles generated when products containing CNTs are sanded depends on the conditions of sanding and the characteristics of the material being sanded. PMID:23204914

  3. Evaluation of Airborne Particle Emissions from Commercial Products Containing Carbon Nanotubes.

    PubMed

    Huang, Guannan; Park, Jae Hong; Cena, Lorenzo G; Shelton, Betsy L; Peters, Thomas M

    2012-10-01

    The emission of the airborne particles from epoxy resin test sticks with different CNT loadings and two commercial products were characterized while sanding with three grit sizes and three disc sander speeds. The total number concentrations, respirable mass concentrations, and particle size number/mass distributions of the emitted particles were measured using a condensation particle counter, an optical particle counter, and a scanning mobility particle sizer. The emitted particles were sampled on a polycarbonate filter and analyzed using electron microscopy. The highest number concentrations (arithmetic mean = 4670 particles/cm(3)) were produced with coarse sandpaper, 2% (by weight) CNT test sticks and medium disc sander speed, whereas the lowest number concentrations (arithmetic mean = 92 particles/cm(3)) were produced with medium sandpaper, 2% CNT test sticks and slow disc sander speed. Respirable mass concentrations were highest (arithmetic mean = 1.01 mg/m(3)) for fine sandpaper, 2% CNT test sticks and medium disc sander speed and lowest (arithmetic mean = 0.20 mg/m(3)) for medium sandpaper, 0% CNT test sticks and medium disc sander speed. For CNT-epoxy samples, airborne particles were primarily micrometer-sized epoxy cores with CNT protrusions. No free CNTs were observed in airborne samples, except for tests conducted with 4% CNT epoxy. The number concentration, mass concentration, and size distribution of airborne particles generated when products containing CNTs are sanded depends on the conditions of sanding and the characteristics of the material being sanded.

  4. Interface of a particle collector with on-line electrochemically-modulated separation system for analysis of airborne radioisotopes

    SciTech Connect

    Duckworth, Douglas {Doug} C

    2005-01-01

    The International Monitoring System is part of the global verification system of the Comprehensive Nuclear-Test-Ban Treaty and comprises an atmospheric radioactivity monitoring network of 80 particulate stations, 40 of which are to be equipped with noble-gas-detection capability. The network is supported by 16 radionuclide laboratories. The equipment has to be tailored to different environments and its reliability is proving to be an operational challenge. A novel device for collecting, concentrating and separating airborne particles in situ is under development through a collaborative effort between Savannah River Technology Center (SRTC) and Oak Ridge National Laboratory (ORNL). This work entails coupling an Aerosol-to-Liquid Particle Extraction System (ALPES) to an electrochemically modulated separation (EMS) cell. The ALPES collects and concentrates airborne particles into a liquid, and the EMS cell separates species based on their affinity for a charged target surface. Preliminary data indicates substantial sensitivity enhancement may be realized by interfacing these devices. The system will allow for rapid field analysis of radionuclides while providing reductions in labor, cost, and turnaround time compared to standard radiometric techniques.

  5. Self-refreshing characteristics of an airborne particle sensor using a bridged paddle oscillator

    NASA Astrophysics Data System (ADS)

    Choi, Eunsuk; Lee, Seung-Beck; Park, Bonghyun; Sul, Onejae

    2016-05-01

    We report on the self-refreshing characteristics of a micromachined airborne particle sensor. The sensor consists of a bridge-type beam having an oscillating paddle-type particle collector at its center. When a positive potential is applied to the paddle, the sensor is able to attract and collect negatively charged airborne particles while oscillating close to its resonant frequency and thereby measure their density from the change in the oscillating phase at ˜10 pg resolution. When the applied potential is removed, the collected particles are detached from the sensor due to momentum transfer from the oscillating paddle, thus demonstrating a self-refreshing capability.

  6. Effects of radioactive hot particles on pig skin

    SciTech Connect

    Kaurin, D.G.; Baum, J.W.; Schaefer, C.W.

    1997-06-01

    The purpose of these studies was to determine the incidence and severity of lesions resulting from very localized deposition of dose to skin from small (< 0.5 mm) discrete radioactive particles as produced in the work environments of nuclear reactors. Hanford mini-pigs were exposed, both on a slightly off the skin, to localized replicate doses from 0.31 to 64 Gy (averaged over 1 cm{sup 2} at 70 {mu}m depth unless noted otherwise) using Sc-46, Yb-175, Tm-170, and fissioned UC{sub 2} isotopes having maximum beta-particle energies from about 0.3 to 3 MeV. Erythema and scabs (indicating ulceration) were scored for up to 71 days post-irradiation. The responses followed normal cumulative probability distributions, and therefore, no true threshold could be defined. Hence, 10 and 50% scab incidence rates were deduced using probit analyses. The lowest dose which produced 10% incidence was about 1 Gy for Yb-175 (0.5 MeV maximum energy) beta particle exposures, and about 3 to 9 Gy for other isotopes. The histopathology of lesions was determined at several doses. Single exposures to doses as large as 1,790 Gy were also given, and results were observed for up to 144 days post-exposure. Severity of detriment was estimated by analyzing the results in terms of lesion diameter, persistence, and infection. Over 1,100 sites were exposed. Only two exposed sites became infected after doses near 5000 Gy; the lesions healed quickly on treatment. 105 refs., 145 figs., 47 tabs.

  7. Size distribution of radioactive particles collected at Tokai, Japan 6 days after the nuclear accident.

    PubMed

    Miyamoto, Yutaka; Yasuda, Kenichiro; Magara, Masaaki

    2014-06-01

    Airborne radioactive particles released by the Fukushima Dai-ichi Nuclear Power Plant (FDNPP) accident in 2011 were collected with a cascade low-pressure impactor at the Japan Atomic Energy Agency (JAEA) in Tokai, Japan, 114 km south of the FDNPP. Size-fractionated samples were collected twice, in the periods of March 17-April 1, 2011, and May 9-13, 2011. These size-fractionated samplings were carried out in the earliest days at a short distance from the FDNPP. Radioactivity of short-lived nuclides (several ten days of half-life) was determined as well as (134)Cs and (137)Cs. The elemental composition of size-fractionated samples was also measured. In the first collection, the activity median aerodynamic diameter (AMAD) of (129m)Te, (140)Ba, (134)Cs, (136)Cs and (137)Cs was 1.5-1.6 μm, while the diameter of (131)I was 0.45 μm. The diameters of (134)Cs and (137)Cs in the second collection were expressed as three peaks at <0.5 μm, 0.94 μm, and 7.8 μm. The (134)Cs/(137)Cs ratio of the first collection was 1.02 in total, but the ratio in the fine fractions was 0.91. A distribution map of (134)Cs/(137)Cs - (136)Cs/(137)Cs ratios was helpful in understanding the change of radioactive Cs composition. The Cs composition of size fractions <0.43 μm and the composition in the 1.1-2.1 μm range (including the AMAD of 1.5-1.6 μm) were similar to the calculated compositions of fuels in the reactors No. 1 and No. 3 at the FDNPP using the ORIGEN-II code. The Cs composition collected in May, 2011 was similar to the calculation results of reactor No. 2 fuel composition. The change of Cs composition implies that the radioactive Cs was released from the three reactors at the FDNPP via different processes.

  8. Partitioning of phthalates among the gas phase, airborne particles and settled dust in indoor environments

    NASA Astrophysics Data System (ADS)

    Weschler, Charles J.; Salthammer, Tunga; Fromme, Hermann

    A critical evaluation of human exposure to phthalate esters in indoor environments requires the determination of their distribution among the gas phase, airborne particles and settled dust. If sorption from the gas phase is the dominant mechanism whereby a given phthalate is associated with both airborne particles and settled dust, there should be a predictable relationship between its particle and dust concentrations. The present paper tests this for six phthalate esters (DMP, DEP, DnBP, DiBP, BBzP and DEHP) that have been measured in both the air and the settled dust of 30 Berlin apartments. The particle concentration, CParticle, of a given phthalate was calculated from its total airborne concentration and the concentration of airborne particles (PM 4). This required knowledge of the particle-gas partition coefficient, Kp, which was estimated from either the saturation vapor pressure ( ps) or the octanol/air partition coefficient ( KOA). For each phthalate in each apartment, the ratio of its particle concentration to its dust concentration ( CParticle/ CDust) was calculated. The median values of this ratio were within an order of magnitude of one another for five of the phthalate esters despite the fact that their vapor pressures span four orders of magnitude. This indicates that measurements of phthalate ester concentrations in settled dust can provide an estimate of their concentration in airborne particles. When the latter information is coupled with measurements of airborne particle concentrations, the gas-phase concentrations of phthalates can also be estimated and, subsequently, the contribution of each of these compartments to indoor phthalate exposures.

  9. Rapid Identification of Airborne Biological Particles by Flow Cytometry, Gas Chromatography, and Genetic Probes.

    DTIC Science & Technology

    1997-09-01

    isolated culture of Heterobasidion annosum. The yeast and bacterial specimens have not been identified, since their identifications require biochemical...RZ-SZAACH. DEVELOPMENr & E-NONEERINO CENTER U.S. AR..!f CHR ICAL AND SIOLOGIC-NL DEFENSE COMNMA1D RAPID IDENTIFICATION OF AIRBORNE BIOLOGICAL...Ground, Maryland 21010-5423 ERRATUM SHEET 30 October 1997 REPORT NO. ERDEC-TR-443 TITLE RAPID IDENTIFICATION OF AIRBORNE BIOLOGICAL PARTICLES BY FLOW

  10. Laboratory Study of Airborne Fallout Particles and Their Time Distribution.

    ERIC Educational Resources Information Center

    Smith, H. A., Jr.; And Others

    1979-01-01

    Samples of filtered airborne particulate, collected daily for the first month after the September 18, 1977 Chinese nuclear detonation, showed fourteen fission products. Fluctuations in the daily fallout activity levels suggested a global fallout orbit time of approximately twenty days. (Author/BB)

  11. Micromorphology and chemistry of airborne particles in Brussels during agriculture working periods in surrounding region.

    PubMed

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

    2008-11-01

    The main objective of our research was to compare the airborne particle micromorphology and chemistry in the Brussels environment during agriculture working periods in the surrounding farming region. We used specific methods and instrumentation that are adapted to the climate peculiarities of the Brussels region, the period of investigations (12 months) and the proposed objectives. For the agricultural works we defined the following six periods: before sowing, sowing, after sowing, before harvest, harvest and after harvest. The results indicate a possible temporal correlation between agricultural work periods and airborne particle concentration, micromorphology and chemistry in the Brabant-Brussels region. For wheat and corn plant-growth periods, the average particle size, defined as the area obtained by a planar projection of the particulate, showed important variations in time. For sugar beet and endive, the average area size variations are less important. The roughness and sphericity parameters for the growth periods of the four different plants also showed significant differences. Many of the larger particulates (> 10 microm) are aggregates of even finer particles coated with many still finer ones. The airborne particle chemistry averages (atomic percentage At%), showed that three constituents (Si, S and Fe) dominate all the samples (except for particles 3-10 microm in size, which contain a relatively large percentage of Al). Applying similar investigation methods to study the correlations between airborne particle dynamics in urban zones and the agriculture working periods in their surrounding regions could be of interest to better understand the complexity of the PM problematic.

  12. Retention of radioactive particles and associated effects in the filter-feeding marine mollusc Mytilus edulis.

    PubMed

    Jaeschke, B C; Lind, O C; Bradshaw, C; Salbu, B

    2015-01-01

    Radioactive particles are aggregates of radioactive atoms that may contain significant activity concentrations. They have been released into the environment from nuclear weapons tests, and from accidents and effluents associated with the nuclear fuel cycle. Aquatic filter-feeders can capture and potentially retain radioactive particles, which could then provide concentrated doses to nearby tissues. This study experimentally investigated the retention and effects of radioactive particles in the blue mussel, Mytilus edulis. Spent fuel particles originating from the Dounreay nuclear establishment, and collected in the field, comprised a U and Al alloy containing fission products such as (137)Cs and (90)Sr/(90)Y. Particles were introduced into mussels in suspension with plankton-food or through implantation in the extrapallial cavity. Of the particles introduced with food, 37% were retained for 70 h, and were found on the siphon or gills, with the notable exception of one particle that was ingested and found in the stomach. Particles not retained seemed to have been actively rejected and expelled by the mussels. The largest and most radioactive particle (estimated dose rate 3.18 ± 0.06 Gyh(-1)) induced a significant increase in Comet tail-DNA %. In one case this particle caused a large white mark (suggesting necrosis) in the mantle tissue with a simultaneous increase in micronucleus frequency observed in the haemolymph collected from the muscle, implying that non-targeted effects of radiation were induced by radiation from the retained particle. White marks found in the tissue were attributed to ionising radiation and physical irritation. The results indicate that current methods used for risk assessment, based upon the absorbed dose equivalent limit and estimating the "no-effect dose" are inadequate for radioactive particle exposures. Knowledge is lacking about the ecological implications of radioactive particles released into the environment, for example potential

  13. Airborne measurements of cloud forming nuclei and aerosol particles at Kennedy Space Center, Florida

    NASA Technical Reports Server (NTRS)

    Radke, L. F.; Langer, G.; Hindman, E. E., II

    1978-01-01

    Results of airborne measurements of the sizes and concentrations of aerosol particles, ice nuclei, and cloud condensation nuclei that were taken at Kennedy Space Center, Florida, are presented along with a detailed description of the instrumentation and measuring capabilities of the University of Washington airborne measuring facility (Douglas B-23). Airborne measurements made at Ft. Collins, Colorado, and Little Rock, Arkansas, during the ferry of the B-23 are presented. The particle concentrations differed significantly between the clean air over Ft. Collins and the hazy air over Little Rock and Kennedy Space Center. The concentrations of cloud condensation nuclei over Kennedy Space Center were typical of polluted eastern seaboard air. Three different instruments were used to measure ice nuclei: one used filters to collect the particles, and the others used optical and acoustical methods to detect ice crystals grown in portable cloud chambers. A comparison of the ice nucleus counts, which are in good agreement, is presented.

  14. Measured concentrations of radioactive particles in air in the vicinity of the Anaconda Uranium Mill

    SciTech Connect

    Momeni, M H; Kisieleski, W E

    1980-02-01

    Concentrations of radioactive particles (U-238, Th-230, Ra-226, and Pb-210) in air were measured in the vicinity of the Anaconda Uranium Mill, Bluewater, New Mexico. Airborne particles were collected at three stations for about two-thirds of a year using a continuous collection method at a sampling rate of 10 L/min, and also were measured in monthly composites collected periodically at four stations using high volume air samplers at a sampling rate of 1400 L/min. The ratios of concentrations of each radionuclide to the concentrations of U-238 indicate that the concentrations of the radionuclides are influenced principally by the proximity of the major sources of emission and the direction of the wind. In all cases, the concentration of Pb-210 exceeded that of U-238. The ratio of Pb-210/U-238 was 12.3 and 13.3 for stations dominated by the emissions from the tailings and ore pads, but was only 1.6 for the station dominated by the yellowcake stack emission. The ratio of the radionuclide concentrations measured by the two methods of sample collection was between 0.8 and 1.2 for uranium, radium, and lead at station 104, but was 0.28 to 1.7 for thorium, radium, and lead at stations 101 and 102. The average concentrations calculated from the measurements made in this study suggest that releases from the Anaconda mill were made well within the existing limits of the maximum permissible concentrations for inhalation exposure of the general public.

  15. Application of the focused ion beam technique in aerosol science: detailed investigation of selected, airborne particles.

    PubMed

    Kaegi, R; Gasser, Ph

    2006-11-01

    The focused ion beam technique was used to fabricate transmission electron microscope lamellas of selected, micrometre-sized airborne particles. Particles were sampled from ambient air on Nuclepore polycarbonate filters and analysed with an environmental scanning electron microscope. A large number of particles between 0.6 and 10 microm in diameter (projected optical equivalent diameter) were detected and analysed using computer-controlled scanning electron microscopy. From the resulting dataset, where the chemistry, morphology and position of each individual particle are stored, two particles were selected for a more detailed investigation. For that purpose, the particle-loaded filter was transferred from the environmental scanning electron microscope to the focused ion beam, where lamellas of the selected particles were fabricated. The definition of a custom coordinate system enabled the relocation of the particles after the transfer. The lamellas were finally analysed with an analytical transmission electron microscope. Internal structure and elemental distribution maps of the interior of the particles provided additional information about the particles, which helped to assign the particles to their sources. The combination of computer-controlled scanning electron microscopy, focused ion beam and transmission electron microscopy offers new possibilities for characterizing airborne particles in great detail, eventually enabling a detailed source apportionment of specific particles. The particle of interest can be selected from a large dataset (e.g. based on chemistry and/or morphology) and then investigated in more detail in the transmission electron microscope.

  16. [Prevalence of radioactive particles in the territory of Byelorussia and their contents in the lungs].

    PubMed

    Petriaev, E P; Sokolik, G A; Leĭnova, S L; Danil'chenko, E M

    1993-01-01

    Examination conducted in 1987--1988 included 200 samples of the autopsy material of subjects who died of various causes in different regions of Byelorussia. It revealed the presence of "hot" particles (i.e. particles with high specific radioactivity) in 50% of the samples taken from the northwest and in 70% of those from the southeast regions. A correlation was found to exist between the radioactive particles content in the soil, air and lungs of residents from the contaminated territory. It was shown that in 1990--1991, in contrast to 1987--1988, the particles content in a single lung sample reduced, which was associated both with mechanical removal of particles and their disintegration and, as a consequence with the accumulation of plutonium in the body. Study of radioactive particles distribution in the whole lung showed that at present they are found primarily in the lower segments.

  17. Fabrication and testing of an airborne ice particle counter

    NASA Technical Reports Server (NTRS)

    Kebabian, P. L.

    1976-01-01

    An optical ice particle counter was proposed as a companion instrument to the GSFC laser nephelometer. By counting ice particles and total cloud particles (both ice and liquid water), these two instruments may be used to study the balance between ice and water in clouds.

  18. Evaluation of radioactive environmental hazards in Area-3, Northern Palmyrides, Central Syria using airborne spectrometric gamma technique.

    PubMed

    Asfahani, J; Aissa, M; Al-Hent, R

    2016-01-01

    Airborne spectrometric gamma data are used in this paper to estimate the degree of radioactive hazard on humanity in Area-3, Northern Palmyrides, Central Syria. Exposure Rate (ER), Absorbed Dose Rate (ADR), Annual Effective Dose Rate (AEDR), and Heat Production (HP) of the eleven radiometric units included in the established lithological scored map in the study area have been computed to evaluate the radiation background influence in humans. The results obtained indicate that a human body in Area-3 is subjected to radiation hazards in the acceptable limits for long duration exposure. The highest radiogenetic heat production values in Area-3 correspond to the phosphatic locations characterized by relatively high values of uranium and thorium.

  19. Novel method for estimation of the indoor-to-outdoor airborne radioactivity ratio following the Fukushima Daiichi Nuclear Power Plant accident.

    PubMed

    Tan, Yanliang; Ishikawa, Tetsuo; Janik, Miroslaw; Tokonami, Shinji; Hosoda, Masahiro; Sorimachi, Atsuyuki; Kearfott, Kimberlee

    2015-12-01

    The accident at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in Japan resulted in significant releases of fission products. While substantial data exist concerning outdoor air radioactivity following the accident, the resulting indoor radioactivity remains pure speculation without a proper method for estimating the ratio of the indoor to outdoor airborne radioactivity, termed the airborne sheltering factor (ASF). Lacking a meaningful value of the ASF, it is difficult to assess the inhalation doses to residents and evacuees even when outdoor radionuclide concentrations are available. A simple model was developed and the key parameters needed to estimate the ASF were obtained through data fitting of selected indoor and outdoor airborne radioactivity measurement data obtained following the accident at a single location. Using the new model with values of the air exchange rate, interior air volume, and the inner surface area of the dwellings, the ASF can be estimated for a variety of dwelling types. Assessment of the inhalation dose to individuals readily follows from the value of the ASF, the person's indoor occupancy factor, and the measured outdoor radioactivity concentration.

  20. Fluorescence of Bacteria, Pollens, and Naturally Occurring Airborne Particles: Excitation/Emission Spectra

    DTIC Science & Technology

    2009-02-01

    biological particles (1–10) are important in the transmission of diseases (11, 12) of humans (e.g., tuberculosis , influenza), farm animals (e.g...the air. Bacteria, rickettsia, viruses, protein toxins, and some neurotoxins produced by microbes have been feared as potential airborne biological

  1. Radioactive particles released to the environment from the Fukushima reactors-Confirmation is still needed.

    PubMed

    Salbu, Brit; Lind, Ole Christian

    2016-10-01

    After severe nuclear events, a major fraction of refractory radionuclides such as U and Pu are released to the environment in the form of radioactive particles. After the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident, Pu isotope ratio signals different from that of global fallout have been reported, indicating that spent fuel particles have been released from the reactors or reactor vessels. Radioactive particles containing (37) Cs and other volatile radionuclides, as well as a series of stable refractory metals (Cs, Fe, Zn, U, etc.), have been identified by several authors claiming that these particles originated from the FDNPP fuel. If so, long-lived radioactive isotopes of the refractory metals should have been identified in these particles. It is therefore most probable that volatile radionuclides released as gases during the accidents have deposited on available surfaces such as fly ash, forming condensation particles during release or transport. If spent fuel particles have been deposited in the FDNPP surroundings, information on particle characteristics influencing ecosystem transport, uptake, and effects is essential for assessing environmental impact and risk. More emphasis should therefore be put on the identification of hot spots in the FDNPP environment followed by the characterization of radioactive particles using nanoanalytical-microanalytical techniques to support environmental monitoring, as recommended in the present study. Integr Environ Assess Manag 2016;12:687-689. © 2016 SETAC.

  2. Spectrum correction algorithm for detectors in airborne radioactivity monitoring equipment NH-UAV based on a ratio processing method

    NASA Astrophysics Data System (ADS)

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

    2015-10-01

    The unmanned aerial vehicle (UAV) radiation monitoring method plays an important role in nuclear accidents emergency. In this research, a spectrum correction algorithm about the UAV airborne radioactivity monitoring equipment NH-UAV was studied to measure the radioactive nuclides within a small area in real time and in a fixed place. The simulation spectra of the high-purity germanium (HPGe) detector and the lanthanum bromide (LaBr3) detector in the equipment were obtained using the Monte Carlo technique. Spectrum correction coefficients were calculated after performing ratio processing techniques about the net peak areas between the double detectors on the detection spectrum of the LaBr3 detector according to the accuracy of the detection spectrum of the HPGe detector. The relationship between the spectrum correction coefficient and the size of the source term was also investigated. A good linear relation exists between the spectrum correction coefficient and the corresponding energy (R2=0.9765). The maximum relative deviation from the real condition reduced from 1.65 to 0.035. The spectrum correction method was verified as feasible.

  3. Identifying airborne metal particles sources near an optoelectronic and semiconductor industrial park

    NASA Astrophysics Data System (ADS)

    Chen, Ho-Wen; Chen, Wei-Yea; Chang, Cheng-Nan; Chuang, Yen-Hsun; Lin, Yu-Hao

    2016-06-01

    The recently developed Central Taiwan Science Park (CTSP) in central Taiwan is home to an optoelectronic and semiconductor industrial cluster. Therefore, exploring the elemental compositions and size distributions of airborne particles emitted from the CTSP would help to prevent pollution. This study analyzed size-fractionated metal-rich particle samples collected in upwind and downwind areas of CTSP during Jan. and Oct. 2013 by using micro-orifice uniform deposited impactor (MOUDI). Correlation analysis, hierarchical cluster analysis and particle mass-size distribution analysis are performed to identify the source of metal-rich particle near the CTSP. Analyses of elemental compositions and particle size distributions emitted from the CTSP revealed that the CTSP emits some metals (V, As, In Ga, Cd and Cu) in the ultrafine particles (< 1 μm). The statistical analysis combines with the particle mass-size distribution analysis could provide useful source identification information. In airborne particles with the size of 0.32 μm, Ga could be a useful pollution index for optoelectronic and semiconductor emission in the CTSP. Meanwhile, the ratios of As/Ga concentration at the particle size of 0.32 μm demonstrates that humans near the CTSP would be potentially exposed to GaAs ultrafine particles. That is, metals such as Ga and As and other metals that are not regulated in Taiwan are potentially harmful to human health.

  4. An analytical electron microscope study of airborne industrial particles in Sosnowiec, Poland

    NASA Astrophysics Data System (ADS)

    Rietmeijer, Frans J. M.; Janeczek, Janusz

    The types and the relative amounts of airborne particles in the city of Sosnowiec (Poland) during 21-22 June, 1994 were identified by analytical electron microscope analyses. They are mostly aspherical angular Al-bearing silica particles (0.1-5.15 μm) and clusters thereof. Carbonaceous particles form sheets of soluble volatile-rich materials (0.3-33.9 μm) and rare soot. Numerous nanometer-sized Al-bearing silica grains and salt minerals are associated with the larger particles. They resulted from inefficient combustion of low-grade coals by the local industries whereby the silica particles are coal impurities that survived combustion. The total particle emission was constant during a 24 h period but silica shards dominated the nighttime emission while carbonaceous particles abounded during the daytime. This study showed that tropospheric particles in regions dominated by inefficient coal combustion are fundamentally different from typical coal fly ash spheres.

  5. Tracing airborne particles after Japan's nuclear plant explosion

    NASA Astrophysics Data System (ADS)

    Takemura, Toshihiko; Nakamura, Hisashi; Nakajima, Teruyuki

    2011-11-01

    The powerful Tohoku earthquake and consequent tsunami that occurred off the east coast of Japan on 11 March 2011 devastated dozens of coastal cities and towns, causing the loss of more than 15,000 lives and leaving close to 4000 people still missing. Although nuclear reactors at the Fukushima Daiichi Nuclear Power Plant, located on the Pacific coast, stopped their operation automatically upon the occurrence of the Mw 9.0 quake [Showstack, 2011], the cooling system for nuclear fuel broke down. From 12 to 16 March, vapor and hydrogen blasts destroyed the buildings that had contained the reactors, resulting in the release into the atmosphere of radioactive materials such as sulfur-35, iodine-131, cesium-134, and cesium-137, which collectively can cause harmful health effects such as tissue damage and increased risk of cancer (particularly in children), depending on dose. Most of those materials emitted from the power plant rained out onto the grounds within its vicinity and forced tens of thousands within a 20-kilometer radius to evacuate (residents to the northwest of the site within about 40 kilometers also were moved from their homes). Some of the radioactive materials were transported and then detected at such distant locations as North America and Europe, although the level of radiation dose was sufficiently low not to affect human health in any significant manner.

  6. Elastic back-scattering patterns via particle surface roughness and orientation from single trapped airborne aerosol particles

    NASA Astrophysics Data System (ADS)

    Fu, Richard; Wang, Chuji; Muñoz, Olga; Videen, Gorden; Santarpia, Joshua L.; Pan, Yong-Le

    2017-01-01

    We demonstrate a method for simultaneously measuring the back-scattering patterns and images of single laser-trapped airborne aerosol particles. This arrangement allows us to observe how the back-scattering patterns change with particle size, shape, surface roughness, orientation, etc. The recoded scattering patterns cover the angular ranges of θ=167.7-180° (including at 180° exactly) and ϕ=0-360° in spherical coordinates. The patterns show that the width of the average speckle intensity islands or rings is inversely proportional to particle size and how the shape of these intensity rings or islands also depends on the surface roughness. For an irregularly shaped particle with substantial roughness, the back-scattering patterns are formed with speckle intensity islands, the size and orientations of these islands depend more on the overall particle size and orientation, but have less relevance to the fine alteration of the surface structure and shapes. The back-scattering intensity at 180° is very sensitive to the particle parameters. It can change from a maximum to a minimum with a change of 0.1% in particle size or refractive index. The method has potential use in characterizing airborne aerosol particles, and may be used to provide back-scattering information for LIDAR applications.

  7. Preparation and quantification of radioactive particles for tracking hydrodynamic behavior in multiphase reactors.

    PubMed

    Yunos, Mohd Amirul Syafiq Mohd; Hussain, Siti Aslina; Yusoff, Hamdan Mohamed; Abdullah, Jaafar

    2014-09-01

    Radioactive particle tracking (RPT) has emerged as a promising and versatile technique that can provide rich information about a variety of multiphase flow systems. However, RPT is not an off-the-shelf technique, and thus, users must customize RPT for their applications. This paper presents a simple procedure for preparing radioactive tracer particles created via irradiation with neutrons from the TRIGA Mark II research reactor. The present study focuses on the performance evaluation of encapsulated gold and scandium particles for applications as individual radioactive tracer particles using qualitative and quantitative neutron activation analysis (NAA) and an X-ray microcomputed tomography (X-ray Micro-CT) scanner installed at the Malaysian Nuclear Agency.

  8. Charging and coagulation of radioactive and nonradioactive particles in the atmosphere

    SciTech Connect

    Kim, Yong-ha; Yiacoumi, Sotira; Nenes, Athanasios; Tsouris, Costas

    2016-01-01

    Charging and coagulation influence one another and impact the particle charge and size distributions in the atmosphere. However, few investigations to date have focused on the coagulation kinetics of atmospheric particles accumulating charge. This study presents three approaches to include mutual effects of charging and coagulation on the microphysical evolution of atmospheric particles such as radioactive particles. The first approach employs ion balance, charge balance, and a bivariate population balance model (PBM) to comprehensively calculate both charge accumulation and coagulation rates of particles. The second approach involves a much simpler description of charging, and uses a monovariate PBM and subsequent effects of charge on particle coagulation. The third approach is further simplified assuming that particles instantaneously reach their steady-state charge distributions. It is found that compared to the other two approaches, the first approach can accurately predict time-dependent changes in the size and charge distributions of particles over a wide size range covering from the free molecule to continuum regimes. The other two approaches can reliably predict both charge accumulation and coagulation rates for particles larger than about 0.04 micrometers and atmospherically relevant conditions. These approaches are applied to investigate coagulation kinetics of particles accumulating charge in a radioactive neutralizer, the urban atmosphere, and an atmospheric system containing radioactive particles. Limitations of the approaches are discussed.

  9. Charging and coagulation of radioactive and nonradioactive particles in the atmosphere

    DOE PAGES

    Kim, Yong-ha; Yiacoumi, Sotira; Nenes, Athanasios; ...

    2016-01-01

    Charging and coagulation influence one another and impact the particle charge and size distributions in the atmosphere. However, few investigations to date have focused on the coagulation kinetics of atmospheric particles accumulating charge. This study presents three approaches to include mutual effects of charging and coagulation on the microphysical evolution of atmospheric particles such as radioactive particles. The first approach employs ion balance, charge balance, and a bivariate population balance model (PBM) to comprehensively calculate both charge accumulation and coagulation rates of particles. The second approach involves a much simpler description of charging, and uses a monovariate PBM and subsequentmore » effects of charge on particle coagulation. The third approach is further simplified assuming that particles instantaneously reach their steady-state charge distributions. It is found that compared to the other two approaches, the first approach can accurately predict time-dependent changes in the size and charge distributions of particles over a wide size range covering from the free molecule to continuum regimes. The other two approaches can reliably predict both charge accumulation and coagulation rates for particles larger than about 0.04 micrometers and atmospherically relevant conditions. These approaches are applied to investigate coagulation kinetics of particles accumulating charge in a radioactive neutralizer, the urban atmosphere, and an atmospheric system containing radioactive particles. Limitations of the approaches are discussed.« less

  10. Direct Characterization of Airborne Particles Associated with Arsenic-rich Mine Tailings: Particle Size Mineralogy and Texture

    SciTech Connect

    M Corriveau; H Jamieson; M Parsons; J Campbell; A Lanzirotti

    2011-12-31

    Windblown and vehicle-raised dust from unvegetated mine tailings can be a human health risk. Airborne particles from As-rich abandoned Au mine tailings from Nova Scotia, Canada have been characterized in terms of particle size, As concentration, As oxidation state, mineral species and texture. Samples were collected in seven aerodynamically fractionated size ranges (0.5-16 {micro}m) using a cascade impactor deployed at three tailings fields. All three sites are used for recreational activities and off-road vehicles were racing on the tailings at two mines during sample collection. Total concentrations of As in the <8 {micro}m fraction varied from 65 to 1040 ng/m{sup 3} of air as measured by proton-induced X-ray emission (PIXE) analysis. The same samples were analysed by synchrotron-based microfocused X-ray absorption near-edge spectroscopy ({micro}XANES) and X-ray diffraction ({micro}XRD) and found to contain multiple As-bearing mineral species, including Fe-As weathering products. The As species present in the dust were similar to those observed in the near-surface tailings. The action of vehicles on the tailings surface may disaggregate material cemented with Fe arsenate and contribute additional fine-grained As-rich particles to airborne dust. Results from this study can be used to help assess the potential human health risks associated with exposure to airborne particles from mine tailings.

  11. Aerosol-fluorescence spectrum analyzer: real-time measurement of emission spectra of airborne biological particles

    NASA Astrophysics Data System (ADS)

    Hill, Steven C.; Pinnick, Ronald G.; Nachman, Paul; Chen, Gang; Chang, Richard K.; Mayo, Michael W.; Fernandez, Gilbert L.

    1995-10-01

    We have assembled an aerosol-fluorescence spectrum analyzer (AFS), which can measure the fluorescence spectra and elastic scattering of airborne particles as they flow through a laser beam. The aerosols traverse a scattering cell where they are illuminated with intense (50 kW/cm 2) light inside the cavity of an argon-ion laser operating at 488 nm. This AFS can obtain fluorescence spectra of individual dye-doped polystyrene microspheres as small as 0.5 mu m in diameter. The spectra obtained from microspheres doped with pink and green-yellow dyes are clearly different. We have also detected the fluorescence spectra of airborne particles (although not single particles) made from various

  12. Formation and alteration of airborne particles in the subway environment.

    PubMed

    Moreno, T; Querol, X; Martins, V; Minguillón, M C; Reche, C; Ku, L H; Eun, H R; Ahn, K H; Capdevila, M; de Miguel, E

    2017-01-25

    Most particles in the rail subway environment are sub-micron sized ferruginous flakes and splinters generated mechanically by frictional wear of brake pads, wheels and rails. To better understand the mechanisms of formation and the alteration processes affecting inhalable particles in subways, PM samples (1-2.5 μm and 2.5-10 μm) were collected in the Barcelona Metro and then studied under a scanning electron microscope. Most particles in these samples are hematitic (up to 88%), with relatively minor amounts of mineral matter (up to 9%) and sulphates (up to 5%). Detailed microscopy (using back scattered and TEM-DRX imaging) reveals how many of the metallic particles comprise the metallic Fe nucleus surrounded by hematite (Fe2O3) and a coating of sulphate and chloride salts mixed with mineral matter (including Ca-carbonates, clay minerals and quartz). These observations record the emission of fine to ultrafine FePM by frictional wear at elevated temperatures that promote rapid partial (or complete) oxidation of the native metal. Water condensing on the PM surface during cooling leads to the adsorption of inorganic mineral particles that coat the iron oxide. The distinctively layered polymineralic structure that results from these processes is peculiar to particles generated in the subway environment and very different from PM typically inhaled outdoors.

  13. SYNTHESIS OF NON-RADIOACTIVE SLURRIES TO SIMULATE THE PROCESSING BEHAVIOR OF PARTICLES IN RADIOACTIVE WASTE SLURRIES 626-G

    SciTech Connect

    Koopman, D.; Lambert, D.; Eibling, R.; Newell, J.; Stone, M.

    2009-09-03

    Process development using non-radioactive analogs to high-level radioactive waste slurries is an established cost effective alternative to working with actual samples of the real waste. Current simulated waste slurries, however, do not capture all of the physical behavior of real waste. New methods of preparing simulants are under investigation along with mechanisms for altering certain properties of finished simulants. These methods have achieved several notable successes recently in the areas of rheology and foaminess. Particle size is also being manipulated more effectively than in the past, though not independently of the rheological properties. The interaction between rheology and foaminess has exhibited counter-intuitive behavior with more viscous slurries being less foamy even though drainage of liquid from the foam lamellae should be inhibited by higher viscosities.

  14. A Micro Aerosol Sensor for the Measurement of Airborne Ultrafine Particles

    PubMed Central

    Zhang, Chao; Zhu, Rong; Yang, Wenming

    2016-01-01

    Particle number concentration and particle size are the two key parameters used to characterize exposure to airborne nanoparticles or ultrafine particles that have attracted the most attention. This paper proposes a simple micro aerosol sensor for detecting the number concentration and particle size of ultrafine particles with diameters from 50 to 253 nm based on electrical diffusion charging. The sensor is composed of a micro channel and a couple of planar electrodes printed on two circuit boards assembled in parallel, which thus integrate charging, precipitating and measurement elements into one chip, the overall size of which is 98 × 38 × 25 mm3. The experiment results demonstrate that the sensor is useful for measuring monodisperse aerosol particles with number concentrations from 300 to 2.5 × 104 /cm3 and particle sizes from 50 to 253 nm. The aerosol sensor has a simple structure and small size, which is favorable for use in handheld devices. PMID:26999156

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

    SciTech Connect

    TAM, P. S.

    2003-05-23

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

  16. Environmental radioactivity in the UK: the airborne geophysical view of dose rate estimates.

    PubMed

    Beamish, David

    2014-12-01

    This study considers UK airborne gamma-ray data obtained through a series of high spatial resolution, low altitude surveys over the past decade. The ground concentrations of the naturally occurring radionuclides Potassium, Thorium and Uranium are converted to air absorbed dose rates and these are used to assess terrestrial exposure levels from both natural and technologically enhanced sources. The high resolution airborne information is also assessed alongside existing knowledge from soil sampling and ground-based measurements of exposure levels. The surveys have sampled an extensive number of the UK lithological bedrock formations and the statistical information provides examples of low dose rate lithologies (the formations that characterise much of southern England) to the highest sustained values associated with granitic terrains. The maximum dose rates (e.g. >300 nGy h(-1)) encountered across the sampled granitic terrains are found to vary by a factor of 2. Excluding granitic terrains, the most spatially extensive dose rates (>50 nGy h(-1)) are found in association with the Mercia Mudstone Group (Triassic argillaceous mudstones) of eastern England. Geological associations between high dose rate and high radon values are also noted. Recent studies of the datasets have revealed the extent of source rock (i.e. bedrock) flux attenuation by soil moisture in conjunction with the density and porosity of the temperate latitude soils found in the UK. The presence or absence of soil cover (and associated presence or absence of attenuation) appears to account for a range of localised variations in the exposure levels encountered. The hypothesis is supported by a study of an extensive combined data set of dose rates obtained from soil sampling and by airborne geophysical survey. With no attenuation factors applied, except those intrinsic to the airborne estimates, a bias to high values of between 10 and 15 nGy h(-1) is observed in the soil data. A wide range of

  17. Simultaneous sampling of indoor and outdoor airborne radioactivity after the Fukushima Daiichi nuclear power plant accident.

    PubMed

    Ishikawa, Tetsuo; Sorimachi, Atsuyuki; Arae, Hideki; Sahoo, Sarata Kumar; Janik, Miroslaw; Hosoda, Masahiro; Tokonami, Shinji

    2014-02-18

    Several studies have estimated inhalation doses for the public because of the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. Most of them were based on measurement of radioactivity in outdoor air and included the assumption that people stayed outdoors all day. Although this assumption gives a conservative estimate, it is not realistic. The "air decontamination factor" (ratio of indoor to outdoor air radionuclide concentrations) was estimated from simultaneous sampling of radioactivity in both inside and outside air of one building. The building was a workplace and located at the National Institute of Radiological Sciences (NIRS) in Chiba Prefecture, Japan. Aerosol-associated radioactive materials in air were collected onto filters, and the filters were analyzed by γ spectrometry at NIRS. The filter sampling was started on March 15, 2011 and was continued for more than 1 year. Several radionuclides, such as (131)I, (134)Cs, and (137)Cs were found by measuring the filters with a germanium detector. The air decontamination factor was around 0.64 for particulate (131)I and 0.58 for (137)Cs. These values could give implications for the ratio of indoor to outdoor radionuclide concentrations after the FDNPP accident for a similar type of building.

  18. Receptor modeling of globally circulating airborne particles collected at Mauna Loa Observatory, Hawaii

    SciTech Connect

    Hermann, D.M.

    1988-01-01

    Weekly airborne particle samples were collected at Mauna Loa Observatory (MLO), Hawaii from February 1979 through May 1985. Receptor models were used to identify sources of airborne particles at MLO, determine compositions of particles from these sources, and assess the relative impacts of them. Major sources of ambient particles at MLO include Asian continental material, oceanic biological production of Se and SO{sub 4} species, marine particles, Asian anthropogenic material, local volcanic emissions, and basalt. Source composition profiles were developed for each component. The Asian continental component represents particles transported from Eastern Asia to the North Pacific, and the component consists of crustal material contaminated by anthropogenic emissions. To account for variations in the relative strengths of anthropogenic and crustal sources, a separate Asian anthropogenic component was also developed. During the dust season, Asian continental material accounts for 80% of total suspended particulate material (TSP) at MLO, oceanic productions of Se and SO{sub 4} 11%, marine particles 2.8%, basalt 1.9%, volcanic emissions 1.7%, and Asian anthropogenic material in excess of Asian continental material 3.2%. During the clean season, the oceanic biological production of Se and SO{sub 4} contributes 62% of TSP at MLO. Continental material contributes 22%, marine particles 6.4%, basalt 2.7%, volcanic emissions 2.4%, and anthropogenic materials in excess of continental material 4.3%.

  19. Application of 252Cf-PDMS to characterize airborne particles deposited in an Antarctic glacier.

    PubMed

    da Cunha, K Dias; Evangelista, H; Dalia, K C; Simões, J C; Barros Leite, C V

    2004-05-05

    The aim of this study is to apply the (252)Cf-PDMS (plasma desorption mass spectrometry) technique to characterize particles deposited in ice samples. This technique allows identification of molecular ions, even large molecules, desorbed from the sample surface, in contrast with PIXE (particle induced X-ray emission) or EDS (energy dispersive spectrometry). Two shallow snow cores obtained from different glacial drainage basins on King George Island ice cap, South Shetland Islands (Antarctica), were analyzed by PDMS. The chemical compounds identified in the ice mass spectra show that the particle contents of both samples were statistically different, indicating a non-homogeneous spatial deposition distribution for the deposited particles. The analysis of the ice mass spectra suggests some possible sources for the airborne particles. The mass spectra of ice samples collected at a site exposed directly to air masses coming from the Drake Passage show a significant contribution of particles from crustal and anthropogenic sources. However, the mass spectra of ice samples taken from a site on a slope towards a local inlet point out a high influence of marine aerosol. Therefore, it was concluded that particles deposited onto the ice cap were attributable to different aerosol sources, besides long-range atmospheric transport. The (252)Cf-PDMS technique can be considered a powerful tool for studies of snow and ice samples, providing important information for understanding the global atmospheric transport and deposition of airborne particles.

  20. Characterization of Hairdresser Exposure to Airborne Particles during Hair Bleaching.

    PubMed

    Nilsson, Patrik T; Marini, Sara; Wierzbicka, Aneta; Kåredal, Monica; Blomgren, Eva; Nielsen, Jörn; Buonanno, Giorgio; Gudmundsson, Anders

    2016-01-01

    Respiratory symptoms among hairdressers are often ascribed to the use of bleaching powders that contain persulfate salts. Such salts can act as allergens and airway irritants but the mechanisms behind the negative health effects are not fully known. In order to understand why some hairdressers experience respiratory symptoms during, and after, sessions of hair bleaching, it is of importance to characterize how exposure occurs. In this work we used time and particle size resolved instrumentation with the aim to measure the concentration of particles that hairdressers are exposed to during sessions of hair bleaching. We also used filter samples to collect particles for quantitative determination of persulfate (S2O8(2-)) content and for analysis by light microscopy. Two different types of bleaching powders were used, one marked as dust-free and one without this marking (denoted regular). The time resolved instrumentation revealed that particles <10 µm were emitted, specifically when the regular powder was prepared and mixed with hydrogen peroxide. In contrast to other research our work also revealed that supercoarse particles (>10 µm) were emitted during application of the bleaching, when both the regular and the dust-free powders were used. The measured level of persulfate, sampled in the breathing zone of the hairdressers, was on average 26 µg m(-3) when the regular powder was used and 11 µg m(-3) when the dust-free powder was used. This indicates that use of dust-free powder does not eliminate exposure to persulfates, it only lowers the concentration. We show that the site of sampling, or position of the hairdresser with regards to the hair being bleached, is of high importance in the determination of persulfate levels and exposure. This work focuses on the physical and chemical characterization of the particles released to the air and the results are important for accurate exposure assessments. Accurate assessments may in turn lead to a better understanding of

  1. Airborne monitoring to distinguish engineered nanomaterials from incidental particles for environmental health and safety

    PubMed Central

    Peters, TM; Elzey, S; Johnson, R; Park, H; Grassian, VH; Maher, T; O'Shaughnessy, P

    2016-01-01

    Two methods were used to distinguish airborne engineered nanomaterials from other airborne particles in a facility that produces nano-structured lithium titanate metal oxide powder. The first method involved off-line analysis of filter samples collected with conventional respirable samplers at each of seven locations (six near production processes and one outdoors). Throughout most of the facility and outdoors, respirable mass concentrations were low (<0.050 mg m−3) and were attributed to particles other than the nanomaterial (<10% by mass titanium determined with inductively coupled plasma atomic emission spectrometry). In contrast, in a single area with extensive material handling, mass concentrations were greatest (0.118 mg m−3) and contained up to 39% +/− 11% lithium titanium, indicating the presence of airborne nanomaterial. Analysis of the filter samples collected in this area by transmission electron microscope and scanning electron microscope revealed that the airborne nanomaterial was associated only with spherical aggregates (clusters of fused 10–80 nm nanoparticles) that were larger than 200 nm. This analysis also showed that nanoparticles in this area were the smallest particles of a larger distribution of submicrometer chain agglomerates likely from welding in an adjacent area of the facility. The second method used two, hand-held, direct-reading, battery-operated instruments to obtain a time series of very fine particle number (<300 nm), respirable mass, and total mass concentration, which were then related to activities within the area of extensive material handling. This activity-based monitoring showed that very fine particle number concentrations (<300 nm) had no apparent correlation to worker activities, but that sharp peaks in the respirable and total mass concentration coincided with loading a hopper and replacing nanomaterial collection bags. These findings were consistent with those from the filter-based method in that they

  2. A computer code to estimate accidental fire and radioactive airborne releases in nuclear fuel cycle facilities: User's manual for FIRIN

    SciTech Connect

    Chan, M.K.; Ballinger, M.Y.; Owczarski, P.C.

    1989-02-01

    This manual describes the technical bases and use of the computer code FIRIN. This code was developed to estimate the source term release of smoke and radioactive particles from potential fires in nuclear fuel cycle facilities. FIRIN is a product of a broader study, Fuel Cycle Accident Analysis, which Pacific Northwest Laboratory conducted for the US Nuclear Regulatory Commission. The technical bases of FIRIN consist of a nonradioactive fire source term model, compartment effects modeling, and radioactive source term models. These three elements interact with each other in the code affecting the course of the fire. This report also serves as a complete FIRIN user's manual. Included are the FIRIN code description with methods/algorithms of calculation and subroutines, code operating instructions with input requirements, and output descriptions. 40 refs., 5 figs., 31 tabs.

  3. Indoor emissions as a primary source of airborne allergenic fungal particles in classrooms.

    PubMed

    Yamamoto, Naomichi; Hospodsky, Denina; Dannemiller, Karen C; Nazaroff, William W; Peccia, Jordan

    2015-04-21

    This study quantifies the influence of ventilation and indoor emissions on concentrations and particle sizes of airborne indoor allergenic fungal taxa and further examines geographical variability, each of which may affect personal exposures to allergenic fungi. Quantitative PCR and multiplexed DNA sequencing were employed to count and identify allergenic fungal aerosol particles indoors and outdoors in seven school classrooms in four different countries. Quantitative diversity analysis was combined with building characterization and mass balance modeling to apportion source contributions of indoor allergenic airborne fungal particles. Mass balance calculations indicate that 70% of indoor fungal aerosol particles and 80% of airborne allergenic fungal taxa were associated with indoor emissions; on average, 81% of allergenic fungi from indoor sources originated from occupant-generated emissions. Principal coordinate analysis revealed geographical variations in fungal communities among sites in China, Europe, and North America (p < 0.05, analysis of similarity), demonstrating that geography may also affect personal exposures to allergenic fungi. Indoor emissions including those released with occupancy contribute more substantially to allergenic fungal exposures in classrooms sampled than do outdoor contributions from ventilation. The results suggest that design and maintenance of buildings to control indoor emissions may enable reduced indoor inhalation exposures to fungal allergens.

  4. Monte Carlo Library Least Square (MCLLS) Method for Multiple Radioactive Particle Tracking in BPR

    NASA Astrophysics Data System (ADS)

    Wang, Zhijian; Lee, Kyoung; Gardner, Robin

    2010-03-01

    In This work, a new method of radioactive particles tracking is proposed. An accurate Detector Response Functions (DRF's) was developed from MCNP5 to generate library for NaI detectors with a significant speed-up factor of 200. This just make possible for the idea of MCLLS method which is used for locating and tracking the radioactive particle in a modular Pebble Bed Reactor (PBR) by searching minimum Chi-square values. The method was tested to work pretty good in our lab condition with a six 2" X 2" NaI detectors array only. This method was introduced in both forward and inverse ways. A single radioactive particle tracking system with three collimated 2" X 2" NaI detectors is used for benchmark purpose.

  5. Speciation of radioactive soil particles in the Fukushima contaminated area by IP autoradiography and microanalyses.

    PubMed

    Mukai, Hiroki; Hatta, Tamao; Kitazawa, Hideaki; Yamada, Hirohisa; Yaita, Tsuyoshi; Kogure, Toshihiro

    2014-11-18

    Radioactive soil particles several tens of micrometers in size were collected from litter soil in the radiation contaminated area by the Fukushima nuclear plant accident and characterized using electron and X-ray microanalyses. The radioactive particles were discriminated by autoradiography using imaging plates (IP) on which microgrids were formed by laser ablation in order to find the particles under microscopy. Fifty radioactive particles were identified and classified into three types from their morphology and chemical composition, namely: (1) aggregates of clay minerals, (2) organic matter containing clay mineral particulates, and (3) weathered biotite originating from local granite. With respect to the second type, dissolution of the organic matter did not reduce the radiation, suggesting that the radionuclides were also fixed by the clay minerals. The weathered biotite grains have a plate-like shape with well-developed cleavages inside the grains, and kaolin group minerals and goethite filling the cleavage spaces. The reduction of the radiation intensity was measured before and after the trimming of the plate edges using a focused ion beam (FIB), to examine whether radioactive cesium primarily sorbed at frayed edges. The radiation was attenuated in proportion to the volume decrease by the edge trimming, implying that radioactive cesium was sorbed uniformly in the porous weathered biotite.

  6. Airborne birch pollen antigens in different particle sizes.

    PubMed

    Rantio-Lehtimäki, A; Viander, M; Koivikko, A

    1994-01-01

    Two particle samplers for ambient air, situated together: a static size-selective bio-aerosol sampler (SSBAS) and a Burkard pollen and spore trap were compared in sampling intact birch pollen grains through one flowering period of Betula (a total of 44 days). The SSBAS trapped pollen grains three times more efficiently than the Burkard trap, but the variations in pollen counts were significantly correlated. In contrast, birch pollen antigenic activity and the pollen count in the Burkard samples were not closely correlated. The antigenic concentration was occasionally high both before and after the pollination period. There was a high birch pollen antigenic activity in particle size classes where intact pollen grains were absent, even on days when the pollen count was very low. Correspondingly, on days with high birch pollen counts in the air, pollen antigenic activity was on several occasions low, indicating that pollen grains were empty of antigenic material. The small particle size classes are especially important to allergic patients because they are able to penetrate immediately into the alveoli and provoke asthmatic reactions. Therefore, aerobiological information systems based on pollen and spore counts should be supplemented with information concerning antigenic activities in the air.

  7. Universal decay law in charged-particle emission and exotic cluster radioactivity.

    PubMed

    Qi, C; Xu, F R; Liotta, R J; Wyss, R

    2009-08-14

    A linear universal decay formula is presented starting from the microscopic mechanism of the charged-particle emission. It relates the half-lives of monopole radioactive decays with the Q values of the outgoing particles as well as the masses and charges of the nuclei involved in the decay. This relation is found to be a generalization of the Geiger-Nuttall law in alpha radioactivity and explains well all known cluster decays. Predictions on the most likely emissions of various clusters are presented.

  8. Computerized control of the procedure for detecting and removing airborne particles in operating rooms.

    PubMed

    Bay, Omer Faruk; Ergül, Nesip

    2004-04-01

    Surgical-site infections are still a major problem in modern medicine. Normal skin fora of patients or healthcare workers causes more than half of all infections following clean surgery, but the importance of airborne particles in this setting remains controversial. The use of ultraclean air in operating rooms has been shown to reduce infection rates significantly. High efficiency particlulate air (HEPA) filters are used in some modern operating rooms. Although the uses of HEPA filters, the air quality should be controlled by another device to make safe the air in operating rooms and intensive care units. In this study, a computerized system was established to control the cleanliness of the air by measuring the presence of airborne particles of varying sizes and numbers in operating rooms. When the maximum values are exceeded, the system warns the authorized people by phone, sound, or displays.

  9. The measurement and interpretation of Br/Pb ratios in airborne particles

    NASA Astrophysics Data System (ADS)

    Harrison, Roy M.; Sturges, W. T.

    Concentrations of bromide in atmospheric particles have commonly been used as an indicator of vehicle-emitted lead, since the two elements are associated in auto exhaust. A depression in the Br/Pb ratio from that in fresh auto exhaust has generally been interpreted in terms of an industrial contribution to airborne lead, despite the known loss of bromine from airborne particles during ageing processes in the atmosphere. In this article the available analytical techniques for determination of Br/Pb ratios are critically evaluated, and the reported values of Br/Pb ratios in ambient air are reviewed. The possible reasons for variability in Br/Pb ratios are discussed and recommendations made for the evaluation of Br/Pb ratio data.

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

    PubMed Central

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

    2016-01-01

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

  11. Evaluation of an electrostatic particle ionization technology for decreasing airborne pathogens in pigs.

    PubMed

    Alonso, Carmen; Raynor, Peter C; Davies, Peter R; Morrison, Robert B; Torremorell, Montserrat

    Influenza A virus (IAV), porcine reproductive and respiratory syndrome virus (PRRSV), porcine epidemic diarrhea virus (PEDV) and Staphylococcus aureus are important swine pathogens capable of being transmitted via aerosols. The electrostatic particle ionization system (EPI) consists of a conductive line that emits negative ions that charge particles electrically resulting in the settling of airborne particles onto surfaces and potentially decreasing the risk of pathogen dissemination. The objectives of this study were to determine the effect of the EPI system on the quantity and viability of IAV, PRRSV, PEDV and S. aureus in experimentally generated aerosols and in aerosols generated by infected animals. Efficiency at removing airborne particles was evaluated as a function of particle size (ranging from 0.4 to 10 µm), distance from the source of ions (1, 2 and 3 m) and relative air humidity (RH 30 vs. 70 %). Aerosols were sampled with the EPI system "off" and "on." Removal efficiency was significantly greater for all pathogens when the EPI line was the closest to the source of aerosols. There was a greater reduction for larger particles ranging between 3.3 and 9 µm, which varied by pathogen. Overall airborne pathogen reduction ranged between 0.5 and 1.9 logs. Viable pathogens were detected with the EPI system "on," but there was a trend to reducing the quantity of viable PRRSV and IAV. There was not a significant effect on the pathogens removal efficiency based on the RH conditions tested. In summary, distance to the source of ions, type of pathogen and particle size influenced the removal efficiency of the EPI system. The reduction in infectious agents in the air by the EPI technology could potentially decrease the microbial exposure for pigs and people in confinement livestock facilities.

  12. Deposition of Selected Airborne Particles into a Microfluidic Flow Cytometer for Bioanalysis

    DTIC Science & Technology

    2008-05-01

    Deposition of Selected Airborne Particles Into a Microfluidic Flow Cytometer for Bioanalysis by Hermes Huang , Yong -Le Pan, Steven C. Hill...Bioanalysis Hermes Huang , Yong -Le Pan, and Richard K. Chang Yale University, New Haven, CT Steven C. Hill Computational and Information...Bioanalysis 5c. PROGRAM ELEMENT NUMBER 5d. PROJECT NUMBER 5e. TASK NUMBER 6. AUTHOR(S) Hermes Huang , Yong -Le Pan, Steven C. Hill, and Richard K

  13. Physical and chemical characterization of airborne particles from welding operations in automotive plants.

    PubMed

    Dasch, Jean; D'Arcy, James

    2008-07-01

    Airborne particles were characterized from six welding operations in three automotive plants, including resistance spot welding, metal inert gas (MIG) welding and tungsten inert gas (TIG) welding of aluminum and resistance spot welding, MIG welding and weld-through sealer of galvanized steel. Particle levels were measured throughout the process area to select a sampling location, followed by intensive particle sampling over one working shift. Temporal trends were measured, and particles were collected on filters to characterize their size and chemistry. In all cases, the particles fell into a bimodal size distribution with very large particles >20 mum in diameter, possibly emitted as spatter or metal expulsions, and very small particles about 1 mum in diameter, possibly formed from condensation of vaporized metal. The mass median aerodynamic diameter was about 1 mum, with only about 7% of the particle mass present as ultrafine particles <100 nm. About half the mass of aluminum welding particles could be accounted for by chemical analysis, with the remainder possibly present as oxygen. Predominant species were organic carbon, elemental carbon, iron, and aluminum. More than 80% of the particle mass could be accounted for from steel welding, primarily present as iron, organic carbon, zinc, and copper. Particle concentrations and elemental concentrations were compared with allowable concentrations as recommended by the Occupational Safety and Health Administration and the American Conference of Governmental Industrial Hygienists. In all cases, workplace levels were at least 11 times lower than recommended levels.

  14. Airborne measurements of gas and particle pollutants during CAREBeijing-2008

    NASA Astrophysics Data System (ADS)

    Zhang, W.; Zhu, T.; Yang, W.; Bai, Z.; Sun, Y. L.; Xu, Y.; Yin, B.; Zhao, X.

    2014-01-01

    Measurements of gaseous pollutants - including ozone (O3), sulfur dioxide (SO2), nitrogen oxides (NOX = NO + NO2), carbon monoxide (CO), particle number concentrations (5.6-560 nm and 0.47-30 μm) - and meteorological parameters (T, RH, P) were conducted during the Campaigns of Air Quality Research in Beijing and Surrounding Regions in 2008 (CAREBeijing-2008), from 27 August through 13 October 2008. The data from a total 18 flights (70 h flight time) from near the surface to 2100 m altitude were obtained with a Yun-12 aircraft in the southern surrounding areas of Beijing (38-40° N, 114-118° E). The objectives of these measurements were to characterize the regional variation of air pollution during and after the Olympics of 2008, determine the importance of air mass trajectories and to evaluate of other factors that influence the pollution characteristics. The results suggest that there are primarily four distinct sources that influenced the magnitude and properties of the pollutants in the measured region based on back-trajectory analysis: (1) southerly transport of air masses from regions with high pollutant emissions, (2) northerly and northeasterly transport of less pollutant air from further away, (3) easterly transport from maritime sources where emissions of gaseous pollutant are less than from the south but still high in particle concentrations, and (4) the transport of air that is a mixture from different regions; that is, the air at all altitudes measured by the aircraft was not all from the same sources. The relatively long-lived CO concentration is shown to be a possible transport tracer of long-range transport from the northwesterly direction, especially at the higher altitudes. Three factors that influenced the size distribution of particles - i.e., air mass transport direction, ground source emissions and meteorological influences - are also discussed.

  15. Estimation of Particle Flux and Remineralization Rate from Radioactive Disequilibrium

    SciTech Connect

    Michael P. Bacon; Roger Francois

    2004-05-24

    Reactive radionuclides, such as the thorium isotopes, show measurable deficiencies in the oceanic water column because of their removal by chemical scavenging due to the particle flux. Measurement of the deficiency, coupled with measurement of the radionuclide concentration in particles, allows a determination of the effective particle sinking velocity. Results to date suggest that the effective particle sinking velocity is remarkably invariant with depth. This leads to the tentative suggestion that POC concentration profiles may, to a good approximation, be used directly to determine length scales for the remineralization of sinking organic matter. Further measurements are in progress to test this idea and to evaluate its limitations. Knowledge of the remineralization length scale is essential to an evaluation of the efficiency of the biological pump as a means for deep sequestering of carbon in the ocean.

  16. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  17. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  18. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  19. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  20. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

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

    PubMed

    Godish, Diana; Godish, Thad

    2008-02-01

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

  2. A Methodology to Monitor Airborne PM10 Dust Particles Using a Small Unmanned Aerial Vehicle

    PubMed Central

    Alvarado, Miguel; Gonzalez, Felipe; Erskine, Peter; Cliff, David; Heuff, Darlene

    2017-01-01

    Throughout the process of coal extraction from surface mines, gases and particles are emitted in the form of fugitive emissions by activities such as hauling, blasting and transportation. As these emissions are diffuse in nature, estimations based upon emission factors and dispersion/advection equations need to be measured directly from the atmosphere. This paper expands upon previous research undertaken to develop a relative methodology to monitor PM10 dust particles produced by mining activities making use of small unmanned aerial vehicles (UAVs). A module sensor using a laser particle counter (OPC-N2 from Alphasense, Great Notley, Essex, UK) was tested. An aerodynamic flow experiment was undertaken to determine the position and length of a sampling probe of the sensing module. Flight tests were conducted in order to demonstrate that the sensor provided data which could be used to calculate the emission rate of a source. Emission rates are a critical variable for further predictive dispersion estimates. First, data collected by the airborne module was verified using a 5.0 m tower in which a TSI DRX 8533 (reference dust monitoring device, TSI, Shoreview, MN, USA) and a duplicate of the module sensor were installed. Second, concentration values collected by the monitoring module attached to the UAV (airborne module) obtaining a percentage error of 1.1%. Finally, emission rates from the source were calculated, with airborne data, obtaining errors as low as 1.2%. These errors are low and indicate that the readings collected with the airborne module are comparable to the TSI DRX and could be used to obtain specific emission factors from fugitive emissions for industrial activities. PMID:28216557

  3. A Methodology to Monitor Airborne PM10 Dust Particles Using a Small Unmanned Aerial Vehicle.

    PubMed

    Alvarado, Miguel; Gonzalez, Felipe; Erskine, Peter; Cliff, David; Heuff, Darlene

    2017-02-14

    Throughout the process of coal extraction from surface mines, gases and particles are emitted in the form of fugitive emissions by activities such as hauling, blasting and transportation. As these emissions are diffuse in nature, estimations based upon emission factors and dispersion/advection equations need to be measured directly from the atmosphere. This paper expands upon previous research undertaken to develop a relative methodology to monitor PM10 dust particles produced by mining activities making use of small unmanned aerial vehicles (UAVs). A module sensor using a laser particle counter (OPC-N2 from Alphasense, Great Notley, Essex, UK) was tested. An aerodynamic flow experiment was undertaken to determine the position and length of a sampling probe of the sensing module. Flight tests were conducted in order to demonstrate that the sensor provided data which could be used to calculate the emission rate of a source. Emission rates are a critical variable for further predictive dispersion estimates. First, data collected by the airborne module was verified using a 5.0 m tower in which a TSI DRX 8533 (reference dust monitoring device, TSI, Shoreview, MN, USA) and a duplicate of the module sensor were installed. Second, concentration values collected by the monitoring module attached to the UAV (airborne module) obtaining a percentage error of 1.1%. Finally, emission rates from the source were calculated, with airborne data, obtaining errors as low as 1.2%. These errors are low and indicate that the readings collected with the airborne module are comparable to the TSI DRX and could be used to obtain specific emission factors from fugitive emissions for industrial activities.

  4. Personal sampling of airborne particles: method performance and data quality.

    PubMed

    Janssen, N A; Hoek, G; Harssema, H; Brunekreef, B

    1998-01-01

    A study of personal exposure to respirable particles (PM10) and fine particles (FP) was conducted in groups of 50-70 year-old adults and primary school children in the Netherlands. Four to eight personal measurements per subject were conducted, on weekdays only. Averaging time was 24 hours. Method performance was evaluated regarding compliance, flow, weighing procedure, field blanks and co-located operation of the personal samplers with stationary methods. Furthermore, the possibility that subjects change their behavior due to the wearing of personal sampling equipment was studied by comparing time activity on days of personal sampling with time activity other weekdays. Compliance was high; 95% of the subjects who agreed to continue participating after the first measurement, successfully completed the study, and, expect for the first two days of FP sampling, over 90% of all personal measurements were successful. All pre and post sampling flow readings were within 10% of the required flow rate of 4 L/min. For PM10 precision of the gravimetric analyses was 2.8 microgram/m3 and 0.7 micrograms/m3 for filters weighted on an analytical and a micro-balance respectively. The detection limit was 10.8 micrograms/m3 and 8.6 micrograms/m3 respectively. For FP, weighing precision was 0.4 micrograms/m3 and the detection limit was 5.3 micrograms/m3. All measurements were above the detection limit. Co-located operation of the personal sampler with stationary samplers gave highly correlated concentration (R > 0.90). Outdoor PM10 concentrations measured with the personal sampler were on average 4% higher compared to a Sierra Anderson (SA) inlet and 9% higher compared to a PM10 Harvard Impactor (HI). With the FP cyclone 6% higher classroom concentrations were measured compared to a PM2.5 HI. Adults spent significantly less time outdoor (0.5 hour) and more time at home (0.9 hour) on days of personal sampling compared to other weekdays. For children no significant differences in time

  5. Effect of airborne particles from selected indoor and outdoor environments on gap-junctional intercellular communication.

    PubMed

    Alink, G M; Sjögren, M; Bos, R P; Doekes, G; Kromhout, H; Scheepers, P T

    1998-08-01

    The effect of airborne particles from diesel exhaust, rubber and metal industry, urban air and biological sources (poultry, pig farming, compost industry) on gap-junctional intercellular communication (GJIC) were compared, using HEPA1c1c7 cells. Particles as such were compared with aqueous and organic extracts. Significant inhibition of GJIC by particle suspensions was only observed for the diesel and rubber samples, and for one biological sample (compost). Up to 83% of the inhibition of the whole suspension could be attributed to the particles as such. Washing the particles with organic solvents (aceton, methanol, hexane) did not result in a significant loss of activity from the particles, although the organic fractions showed a significant activity towards GJIC. More active organics was eluted from the rubber industry particles than from the diesel particles by the organic solvent. It is suggested that cancer promoting potential as measured by inhibition of GJIC may vary widely depending on the particle source, and that this effect may be exerted by the particles as such and/or by means of tightly bound bio-active material to the surface.

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

    SciTech Connect

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

    2014-06-15

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

  7. Comparison of deposited surface area of airborne ultrafine particles generated from two welding processes.

    PubMed

    Gomes, J F; Albuquerque, P C; Miranda, Rosa M; Santos, Telmo G; Vieira, M T

    2012-09-01

    This article describes work performed on the assessment of the levels of airborne ultrafine particles emitted in two welding processes metal-active gas (MAG) of carbon steel and friction-stir welding (FSW) of aluminium in terms of deposited area in alveolar tract of the lung using a nanoparticle surface area monitor analyser. The obtained results showed the dependence from process parameters on emitted ultrafine particles and clearly demonstrated the presence of ultrafine particles, when compared with background levels. The obtained results showed that the process that results on the lower levels of alveolar-deposited surface area is FSW, unlike MAG. Nevertheless, all the tested processes resulted in important doses of ultrafine particles that are to be deposited in the human lung of exposed workers.

  8. Airborne dust and soil particles at the Phoenix landing site, Mars

    NASA Astrophysics Data System (ADS)

    Madsen, M. B.; Drube, L.; Goetz, W.; Leer, K.; Falkenberg, T. V.; Gunnlaugsson, H. P.; Haspang, M. P.; Hviid, S. F.; Ellehøj, M. D.; Lemmon, M. T.

    2009-04-01

    The three iSweep targets on the Phoenix lander instrument deck utilize permanent magnets and 6 different background colors for studies of airborne dust [1]. The name iSweep is short for Improved Sweep Magnet experiments and derives from MER heritage [2, 3] as the rovers carried a sweep magnet, which is a very strong ring magnet built into an aluminum structure. Airborne dust is attracted and held by the magnet and the pattern formed depends on magnetic properties of the dust. The visible/near-infrared spectra acquired of the iSweep are rather similar to typical Martian dust and soil spectra. Because of the multiple background colors of the iSweeps the effect of the translucence of thin dust layers can be studied. This is used to estimate the rate of dust accumulation and will be used to evaluate light scattering properties of the particles. Some particles raised by the retro-rockets during the final descent came to rest on the lander deck and spectra of these particles are studied and compared with those of airborne dust and with spectra obtained from other missions. High resolution images acquired by the Optical Microscope (OM) [4] showed subtle differences between different Phoenix soil samples in terms of particle size and color. Most samples contain orange dust (particles smaller than 10 micrometer) as their major component and silt-sized (50-80 micrometer large) subrounded particles. Both particle types are substantially magnetic. Based on results from the Mars Exploration Rovers, the magnetization of the silt-sized particles is believed to be caused by magnetite. Morphology, texture and color of these particles (ranging from colorless, red-brown to almost black) suggest a multiple origin: The darkest particles probably represent lithic fragments, while the brighter ones could be impact or volcanic glasses. [1] Leer K. et al. (2008) JGR, 113, E00A16. [2] Madsen M.B. et al. (2003) JGR, 108, 8069. [3] Madsen M.B. et al. (2008) JGR (in print). [4] Hecht M.H. et

  9. Characterization and Control of Airborne Particles Emitted During Production of Epoxy / Carbon Nanotube Nanocomposites

    PubMed Central

    Cena, Lorenzo G.; Peters, Thomas M.

    2016-01-01

    This work characterized airborne particles that were generated from the weighing of bulk, multi-wall carbon nanotubes (CNTs) and the manual sanding of epoxy test samples reinforced with CNTs. It also evaluated the effectiveness of three local exhaust ventilation (LEV) conditions (no LEV, custom fume hood, and biosafety cabinet) for control of particles generated during sanding of CNT-epoxy nanocomposites. Particle number and respirable mass concentrations were measured using an optical particle counter (OPC) and a condensation particle counter (CPC), and particle morphology was assessed by transmission electron microscopy. The ratios of the geometric mean (GM) concentrations measured during the process to that measured in the background (P/B ratios) were used as indices of the impact of the process and the LEVs on observed concentrations. Processing CNT-epoxy nanocomposites materials released respirable size airborne particles (P/B ratio: weighing = 1.79; sanding = 5.90) but generally no nanoparticles (P/B ratiô1). The particles generated during sanding were predominately micron-sized with protruding CNTs and very different from bulk CNTs that tended to remain in large (>1 μm) tangled clusters. Respirable mass concentrations in the operator’s breathing zone were lower when sanding was performed in the biological safety cabinet (GM = 0.20 μg/m3) compared to those with no LEV (GM = 2.68 μg/m3) or those when sanding was performed inside the fume hood (GM = 21.4 μg/m3; p-value < 0.0001). The poor performance of the custom fume hood used in this study may have been exacerbated by its lack of a front sash and rear baffles and its low face velocity (0.39 m/sec). PMID:21253981

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

    PubMed

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

    2014-06-01

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

  11. A Novel Size-Selective Airborne Particle Sampling Instrument (Wras) for Health Risk Evaluation

    NASA Astrophysics Data System (ADS)

    Gnewuch, H.; Muir, R.; Gorbunov, B.; Priest, N. D.; Jackson, P. R.

    Health risks associated with inhalation of airborne particles are known to be influenced by particle sizes. A reliable, size resolving sampler, classifying particles in size ranges from 2 nm—30 μm and suitable for use in the field would be beneficial in investigating health risks associated with inhalation of airborne particles. A review of current aerosol samplers highlighted a number of limitations. These could be overcome by combining an inertial deposition impactor with a diffusion collector in a single device. The instrument was designed for analysing mass size distributions. Calibration was carried out using a number of recognised techniques. The instrument was tested in the field by collecting size resolved samples of lead containing aerosols present at workplaces in factories producing crystal glass. The mass deposited on each substrate proved sufficient to be detected and measured using atomic absorption spectroscopy. Mass size distributions of lead were produced and the proportion of lead present in the aerosol nanofraction calculated and varied from 10% to 70% by weight.

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

    PubMed Central

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

    2015-01-01

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

  13. A Lagrangian particle model to predict the airborne spread of foot-and-mouth disease virus

    NASA Astrophysics Data System (ADS)

    Mayer, D.; Reiczigel, J.; Rubel, F.

    Airborne spread of bioaerosols in the boundary layer over a complex terrain is simulated using a Lagrangian particle model, and applied to modelling the airborne spread of foot-and-mouth disease (FMD) virus. Two case studies are made with study domains located in a hilly region in the northwest of the Styrian capital Graz, the second largest town in Austria. Mountainous terrain as well as inhomogeneous and time varying meteorological conditions prevent from application of so far used Gaussian dispersion models, while the proposed model can handle these realistically. In the model, trajectories of several thousands of particles are computed and the distribution of virus concentration near the ground is calculated. This allows to assess risk of infection areas with respect to animal species of interest, such as cattle, swine or sheep. Meteorological input data like wind field and other variables necessary to compute turbulence were taken from the new pre-operational version of the non-hydrostatic numerical weather prediction model LMK ( Lokal-Modell-Kürzestfrist) running at the German weather service DWD ( Deutscher Wetterdienst). The LMK model provides meteorological parameters with a spatial resolution of about 2.8 km. To account for the spatial resolution of 400 m used by the Lagrangian particle model, the initial wind field is interpolated upon the finer grid by a mass consistent interpolation method. Case studies depict a significant influence of local wind systems on the spread of virus. Higher virus concentrations at the upwind side of the hills and marginal concentrations in the lee are well observable, as well as canalization effects by valleys. The study demonstrates that the Lagrangian particle model is an appropriate tool for risk assessment of airborne spread of virus by taking into account the realistic orographic and meteorological conditions.

  14. Measurements of Ultra-fine and Fine Aerosol Particles over Siberia: Large-scale Airborne Campaigns

    NASA Astrophysics Data System (ADS)

    Arshinov, Mikhail; Paris, Jean-Daniel; Stohl, Andreas; Belan, Boris; Ciais, Philippe; Nédélec, Philippe

    2010-05-01

    In this paper we discuss the results of in-situ measurements of ultra-fine and fine aerosol particles carried out in the troposphere from 500 to 7000 m in the framework of several International and Russian State Projects. Number concentrations of ultra-fine and fine aerosol particles measured during intensive airborne campaigns are presented. Measurements carried over a great part of Siberia were focused on particles with diameters from 3 to 21 nm to study new particle formation in the free/upper troposphere over middle and high latitudes of Asia, which is the most unexplored region of the Northern Hemisphere. Joint International airborne surveys were performed along the following routes: Novosibirsk-Salekhard-Khatanga-Chokurdakh-Pevek-Yakutsk-Mirny-Novosibirsk (YAK-AEROSIB/PLARCAT2008 Project) and Novosibirsk-Mirny-Yakutsk-Lensk-Bratsk-Novosibirsk (YAK-AEROSIB Project). The flights over Lake Baikal was conducted under Russian State contract. Concentrations of ultra-fine and fine particles were measured with automated diffusion battery (ADB, designed by ICKC SB RAS, Novosibirsk, Russia) modified for airborne applications. The airborne ADB coupled with CPC has an additional aspiration unit to compensate ambient pressure and changing flow rate. It enabled to classify nanoparticles in three size ranges: 3-6 nm, 6-21 nm, and 21-200 nm. To identify new particle formation events we used similar specific criteria as Young et al. (2007): (1) N3-6nm >10 cm-3, (2) R1=N3-6/N621 >1 and R2=N321/N21200 >0.5. So when one of the ratios R1 or R2 tends to decrease to the above limits the new particle formation is weakened. It is very important to notice that space scale where new particle formation was observed is rather large. All the events revealed in the FT occurred under clean air conditions (low CO mixing ratios). Measurements carried out in the atmospheric boundary layer over Baikal Lake did not reveal any event of new particle formation. Concentrations of ultra

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

    SciTech Connect

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

    2014-01-01

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

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

    SciTech Connect

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

    1986-12-01

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

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

    PubMed

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

    2016-06-21

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

  18. Characterization of airborne particles generated from metal active gas welding process.

    PubMed

    Guerreiro, C; Gomes, J F; Carvalho, P; Santos, T J G; Miranda, R M; Albuquerque, P

    2014-05-01

    This study is focused on the characterization of particles emitted in the metal active gas welding of carbon steel using mixture of Ar + CO2, and intends to analyze which are the main process parameters that influence the emission itself. It was found that the amount of emitted particles (measured by particle number and alveolar deposited surface area) are clearly dependent on the distance to the welding front and also on the main welding parameters, namely the current intensity and heat input in the welding process. The emission of airborne fine particles seems to increase with the current intensity as fume-formation rate does. When comparing the tested gas mixtures, higher emissions are observed for more oxidant mixtures, that is, mixtures with higher CO2 content, which result in higher arc stability. These mixtures originate higher concentrations of fine particles (as measured by number of particles by cm(3) of air) and higher values of alveolar deposited surface area of particles, thus resulting in a more severe worker's exposure.

  19. Development and calibration of a real-time airborne radioactivity monitor using direct gamma-ray spectrometry with two scintillation detectors.

    PubMed

    Casanovas, R; Morant, J J; Salvadó, M

    2014-07-01

    The implementation of in-situ gamma-ray spectrometry in an automatic real-time environmental radiation surveillance network can help to identify and characterize abnormal radioactivity increases quickly. For this reason, a Real-time Airborne Radioactivity Monitor using direct gamma-ray spectrometry with two scintillation detectors (RARM-D2) was developed. The two scintillation detectors in the RARM-D2 are strategically shielded with Pb to permit the separate measurement of the airborne isotopes with respect to the deposited isotopes.In this paper, we describe the main aspects of the development and calibration of the RARM-D2 when using NaI(Tl) or LaBr3(Ce) detectors. The calibration of the monitor was performed experimentally with the exception of the efficiency curve, which was set using Monte Carlo (MC) simulations with the EGS5 code system. Prior to setting the efficiency curve, the effect of the radioactive source term size on the efficiency calculations was studied for the gamma-rays from (137)Cs. Finally, to study the measurement capabilities of the RARM-D2, the minimum detectable activity concentrations for (131)I and (137)Cs were calculated for typical spectra at different integration times.

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

    PubMed

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

    2002-05-01

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

  1. A simultaneous charge and size measurement method for individual airborne particles using digital holographic particle imaging

    NASA Astrophysics Data System (ADS)

    Hammond, Adam; Dou, Zhongwang; Liang, Zach; Meng, Hui

    2016-11-01

    Recently, significant inquiry to understand the effects of particle charge on particle laden flow have been made, particularly in the study of Lagrangian particle-pair statistics. Quantification of individual particle charge allows relation of inter-particle electric forces and turbulence-induced forces. Here we offer a simultaneous, individual particle charge and size measurement technique utilizing in-line digital holographic Particle Tracking Velocimetry (hPTV). The method measures particle electric mobility through its velocity response within a uniform electric field using a sequence of holograms, next the particle diameter is measured with the same holograms using a matched-filter developed by Lu et al. (2012) as an input for calculation of charge. Consequently, a benefit of this method is that particle charge is calculated on the individual level, versus a mean charge calculated from a group of particles, offering improved estimations of charge distributions for studies of particle laden flow. This work was supported by NSF CBET-0967407 and CBET-0967349.

  2. Characterization of Exposures to Airborne Nanoscale Particles During Friction Stir Welding of Aluminum

    PubMed Central

    Pfefferkorn, Frank E.; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; Mccarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M. Abbas; Gruetzmacher, George; Hoover, Mark D.

    2010-01-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 μm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 μm) with 1-s resolution, lung deposited surface areas, and PM2.5 concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 μm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at ∼30 and ∼550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at ∼4.0 × 105 particles cm−3, whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm−3, depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10–100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) μg m−3; the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may exist, especially in larger scale industrial

  3. Characterization of exposures to airborne nanoscale particles during friction stir welding of aluminum.

    PubMed

    Pfefferkorn, Frank E; Bello, Dhimiter; Haddad, Gilbert; Park, Ji-Young; Powell, Maria; McCarthy, Jon; Bunker, Kristin Lee; Fehrenbacher, Axel; Jeon, Yongho; Virji, M Abbas; Gruetzmacher, George; Hoover, Mark D

    2010-07-01

    Friction stir welding (FSW) is considered one of the most significant developments in joining technology over the last half century. Its industrial applications are growing steadily and so are the number of workers using this technology. To date, there are no reports on airborne exposures during FSW. The objective of this study was to investigate possible emissions of nanoscale (<100 nm) and fine (<1 microm) aerosols during FSW of two aluminum alloys in a laboratory setting and characterize their physicochemical composition. Several instruments measured size distributions (5 nm to 20 microm) with 1-s resolution, lung deposited surface areas, and PM(2.5) concentrations at the source and at the breathing zone (BZ). A wide range aerosol sampling system positioned at the BZ collected integrated samples in 12 stages (2 nm to 20 microm) that were analyzed for several metals using inductively coupled plasma mass spectrometry. Airborne aerosol was directly collected onto several transmission electron microscope grids and the morphology and chemical composition of collected particles were characterized extensively. FSW generates high concentrations of ultrafine and submicrometer particles. The size distribution was bimodal, with maxima at approximately 30 and approximately 550 nm. The mean total particle number concentration at the 30 nm peak was relatively stable at approximately 4.0 x 10(5) particles cm(-3), whereas the arithmetic mean counts at the 550 nm peak varied between 1500 and 7200 particles cm(-3), depending on the test conditions. The BZ concentrations were lower than the source concentrations by 10-100 times at their respective peak maxima and showed higher variability. The daylong average metal-specific concentrations were 2.0 (Zn), 1.4 (Al), and 0.24 (Fe) microg m(-3); the estimated average peak concentrations were an order of magnitude higher. Potential for significant exposures to fine and ultrafine aerosols, particularly of Al, Fe, and Zn, during FSW may

  4. Monitor of the concentration of particles of dense radioactive materials in a stream of air

    DOEpatents

    Yule, Thomas J.

    1979-01-01

    A monitor of the concentration of particles of radioactive materials such as plutonium oxide in diameters as small as 1/2 micron includes in combination a first stage comprising a plurality of virtual impactors, a second stage comprising a further plurality of virtual impactors, a collector for concentrating particulate material, a radiation detector disposed near the collector to respond to radiation from collected material and means for moving a stream of air, possibly containing particulate contaminants, through the apparatus.

  5. Discriminating bacterial spores from inert airborne particles by classification of optical scattering patterns

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni F.; Pan, Yongle; Videen, Gorden

    2014-05-01

    Scattering patterns are made available by the TAOS (Two-dimensional Angle-resolved Optical Scattering) method, which consists of detecting micrometer-sized single airborne aerosol particles and collecting the intensity of the light they scatter from a pulsed, monochromatic laser beam. TAOS patterns have been classified by a learning machine, the training stage of which depends on many control parameters. Patterns due to single bacterial spores (Bq class) have to be discriminated from those produced by outdoor aerosol particles (Kq set) and diesel soot aggregates (sq set), where both Kq and sq are assumed not to contain patterns of bacterial origin. This work describes two directions along which classification continues to develop: the enlargement of the control parameter set and the simultaneous processing of two areas (sectors) selected from the TAOS pattern. The latter algorithm is meant to make the classifier sensitive to simmetry exhibited by some patterns. The available classification scheme is summarized, as well as the rule by which discrimination is rated off-line. Discrimination based on one pattern sector alone scores fewer than 15% false negatives (misclassified Bq patterns) and false positives from Kq and sq. Discrimination based on the symmetry of two pattern sectors fails to recognize 30% of the Bq (bacterial) patterns, whereas < 5% Kq (environmental) patterns are assigned to the Bq class; false positives from sq (diesel) patterns drop to zero. The issue of false positives is briefly discussed in relation to the fraction of airborne bacteria found in aerosols.

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

    NASA Astrophysics Data System (ADS)

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

    2014-10-01

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

  7. The control by ventilation of airborne bacterial transfer between hospital patients, and its assessment by means of a particle tracer

    PubMed Central

    Foord, N.; Lidwell, O. M.

    1972-01-01

    A simple and convenient particle tracer for studies of the effectiveness of isolation units and other places in limiting the airborne transfer of bacteria is described. Particles of potassium iodide 7-8 μm. diameter are generated by spraying from solution and collected on membrane filters. The particles can be identified by development with 0·1% acid palladium chloride solution, when dark brown spots approximately 100 μm. in diameter are produced. ImagesPlate 1 PMID:4503869

  8. Laboratory testing of airborne brake wear particle emissions using a dynamometer system under urban city driving cycles

    NASA Astrophysics Data System (ADS)

    Hagino, Hiroyuki; Oyama, Motoaki; Sasaki, Sousuke

    2016-04-01

    To measure driving-distance-based mass emission factors for airborne brake wear particulate matter (PM; i.e., brake wear particles) related to the non-asbestos organic friction of brake assembly materials (pads and lining), and to characterize the components of brake wear particles, a brake wear dynamometer with a constant-volume sampling system was developed. Only a limited number of studies have investigated brake emissions under urban city driving cycles that correspond to the tailpipe emission test (i.e., JC08 or JE05 mode of Japanese tailpipe emission test cycles). The tests were performed using two passenger cars and one middle-class truck. The observed airborne brake wear particle emissions ranged from 0.04 to 1.4 mg/km/vehicle for PM10 (particles up to 10 μm (in size), and from 0.04 to 1.2 mg/km/vehicle for PM2.5. The proportion of brake wear debris emitted as airborne brake wear particles was 2-21% of the mass of wear. Oxygenated carbonaceous components were included in the airborne PM but not in the original friction material, which indicates that changes in carbon composition occurred during the abrasion process. Furthermore, this study identified the key tracers of brake wear particles (e.g., Fe, Cu, Ba, and Sb) at emission levels comparable to traffic-related atmospheric environments.

  9. Characterization of airborne particles at a high-btu coal-gasification pilot plant.

    PubMed

    Davidson, C I; Santhanam, S; Stetter, J R; Flotard, R D; Gebert, E

    1982-12-01

    Airborne particles in fugitive emissions have been measured at a slagging fixed-bed coal-gasification pilot plant using lignite. Sampling was conducted during shutdown operations and opening of the gasifier following an aborted startup. Aerosol collected with a Sierra high-volume impactor was subjected to analysis by gas chromatography, mass spectrometry, and scanning electron microscopy; aerosol collected with an Andersen low-volume impactor was subjected to flameless atomic absorption analysis. The data show that the bulk of the trace organic material is associated with small particles: these data are similar to data on ambient air reported in the literature. Particle morphologies resemble those of fly ash from coal combustion, including smooth spheres, vesicular spheres, and crystalline material. Trace element size distributions are bimodal and resemble data for ambient air. Pb-containing particles are generally submicron, while particles containing Al, Fe, and other crustal species are mostly of supermicron size. Aluminum-based aerosol enrichment factors calculated from the lignite composition show that the composition of the aerosol resembles that of the coal, with the exception of modest enrichments of Mg, Na, As, and Pb in the submicron size range. Aerosol enrichment factors based on the earth's crustal composition are somewhat greater than those based on coal composition for several elements, suggesting potential errors in using crustal enrichment data to investigate chemical fractionation during aerosol formation.

  10. Size and composition of airborne particles from pavement wear, tires, and traction sanding.

    PubMed

    Kupiainen, Kaarle J; Tervahattu, Heikki; Räisänen, Mika; Mäkelä, Timo; Aurela, Minna; Hillamo, Risto

    2005-02-01

    Mineral matter is an important component of airborne particles in urban areas. In northern cities of the world, mineral matter dominates PM10 during spring because of enhanced road abrasion caused by the use of antiskid methods, including studded tires and traction sanding. In this study, factors that affect formation of abrasion components of springtime road dust were assessed. Effects of traction sanding and tires on concentrations, mass size distribution, and composition of the particles were studied in a test facility. Lowest particle concentrations were observed in tests without traction sanding. The concentrations increased when traction sand was introduced and continued to increase as a function of the amount of aggregate dispersed. Emissions were additionally affected by type of tire, properties of traction sand aggregate, and driving speed. Aggregates with high fragmentation resistance and coarse grain size distribution had the lowest emissions. Over 90% of PM10 was mineral particles. Mineralogy of the dust and source apportionment showed that they originated from both traction sand and pavement aggregates. The remaining portion was mostly carbonaceous and originated from tires and road bitumen. Mass size distributions were dominated by coarse particles. Contribution of fine and submicron size ranges were approximately 15 and 10% in PM10, respectively.

  11. Estimating and interpretation of radioactive heat production using airborne gamma-ray survey data of Gabal Arrubushi area, Central Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Youssef, Mohamed A. S.

    2016-02-01

    The present work deals with mapping of radioactive heat production from rocks in the Gabal Arrubushi area in the Central Eastern Desert of Egypt based on airborne spectral gamma-ray survey data. The results show that the radioactive heat production in the areas ranges from 0.01 μWm-3 to 5.2 μWm-3. Granites, muscovite and sericite schists in the western part of Gabal Arrubushi area have abnormally high radioactive heat production values from 2.57 μWm-3 to 4.44 μWm-3. Meanwhile, the higher averages of radioactive heat production of these rock units change from 1.21 μWm-3 to 1.5 μWm-3. The intermediate averages of heat production of felsitic mylonite schist, chlorite schist, felsites, amphibolites and Hammamat sediments are below the crustal average value range, i.e., from 0.8 μWm-3 to 1.2 μWm-3. The lowest averages of heat production values are less than 0.8 μWm-3 and found in the following rock units: Wadi sediments, rhyolites, andesites, gabbro and serpentinites.

  12. Environmental hazards and distribution of radioactive black sand along the Rosetta coastal zone in Egypt using airborne spectrometric and remote sensing data.

    PubMed

    Kaiser, M F; Aziz, A M; Ghieth, B M

    2014-11-01

    High-resolution airborne gamma ray spectrometry, conducted in 2003, was used to estimate radioactive elements spatial abundance along the Rosetta coastal zone area. It was noticed that both Uranium and Thorium are concentrated in the black sand deposits along the beach. In contrary, Potassium was observed in high level abundance at the cultivated Nile Delta lands due to the accumulated usage of fertilizers. Exposure Rate (ER), Absorbed Dose Rate (ADR) and Annual Effective Dose Rate (AEDR) were calculated to evaluate the radiation background influence in human. Results indicated that the human body in the study sites is subjected to radiation hazards exceeds the accepted limit for long duration exposure. In addition, the areas covered by the highest concentration of Uranium and Thorium show the highest level of radiogenic heat production. Detection the environmental hazards of the radioactive black sands in the study site encouraged this research to monitor the spatial and temporal distribution of these sediments. The Landsat Thematic Mapper images acquired in 1990, 2003 and 2013 were analyzed using remote sensing image processing techniques. Image enhancements, classification and changes detection indicated a positive significant relationship between the patterns of coastline changes and distribution of the radioactive black sand in the study sites. The radioactive black sands are usually concentrated in the eroded areas. Therefore, in 1990 high concentration of the radioactive black sands were observed along the eastern and western flanks of the Rosetta promontory. Distribution of these sediments decreased due to the construction of the protective sea walls. Most of the radioactive black sands are transported toward the east in Abu Khashaba bay under the effect of the longshore currents and toward the west in Alexandria and Abu Quir bay under the action of the seasonal reverse currents.

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

    NASA Astrophysics Data System (ADS)

    Lazzaro, A.; Meola, M.

    2015-12-01

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

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

    PubMed

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

    2012-06-15

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

  15. A new look at inhalable metalliferous airborne particles on rail subway platforms.

    PubMed

    Moreno, Teresa; Martins, Vânia; Querol, Xavier; Jones, Tim; BéruBé, Kelly; Minguillón, Maria Cruz; Amato, Fulvio; Capdevila, Marta; de Miguel, Eladio; Centelles, Sonia; Gibbons, Wes

    2015-02-01

    Most particles breathed on rail subway platforms are highly ferruginous (FePM) and extremely small (nanometric to a few microns in size). High magnification observations of particle texture and chemistry on airborne PM₁₀ samples collected from the Barcelona Metro, combined with published experimental work on particle generation by frictional sliding, allow us to propose a general model to explain the origin of most subway FePM. Particle generation occurs by mechanical wear at the brake-wheel and wheel-rail interfaces, where magnetic metallic flakes and splinters are released and undergo progressive atmospheric oxidation from metallic iron to magnetite and maghemite. Flakes of magnetite typically comprise mottled mosaics of octahedral nanocrystals (10-20 nm) that become pseudomorphed by maghemite. Continued oxidation results in extensive alteration of the magnetic nanostructure to more rounded aggregates of non-magnetic hematite nanocrystals, with magnetic precursors (including iron metal) still preserved in some particle cores. Particles derived from steel wheel and rails contain a characteristic trace element chemistry, typically with Mn/Fe=0.01. Flakes released from brakes are chemically very distinctive, depending on the pad composition, being always carbonaceous, commonly barium-rich, and texturally inhomogeneous, with trace elements present in nanominerals incorporated within the crystalline structure. In the studied subway lines of Barcelona at least there appears to be only a minimal aerosol contribution from high temperature processes such as sparking. To date there is no strong evidence that these chemically and texturally complex inhalable metallic materials are any more or less toxic than street-level urban particles, and as with outdoor air, the priority in subway air quality should be to reduce high mass concentrations of aerosol present in some stations.

  16. Atmospheric Solids Analysis Probe Mass Spectrometry: A New Approach for Airborne Particle Analysis

    SciTech Connect

    Bruns, Emily A.; Perraud, Veronique M.; Greaves, John; Finlayson-Pitts, Barbara J.

    2010-07-15

    Secondary organic aerosols (SOA) formed in the atmosphere from the condensation of semivolatile oxidation products are a significant component of airborne particles which have deleterious effects on health, visibility, and climate. In this study, atmospheric solids analysis probe mass spectrometry (ASAP-MS) is applied for the first time to the identification of organics in particles from laboratory systems as well as from ambient air. SOA were generated in the laboratory from the ozonolysis of r-pinene and isoprene, as well as from NO3 oxidation of r-pinene, and ambient air was sampled at forested and suburban sites. Particles were collected by impaction on ZnSe disks, analyzed by Fourier transform-infrared spectroscopy (FT-IR) and then transferred to an ASAP-MS probe for further analysis. ASAP-MS data for the laboratory-generated samples show peaks from wellknown products of these reactions, and higher molecular weight oligomers are present in both laboratory and ambient samples. Oligomeric products are shown to be present in the NO3 reaction products for the first time. A major advantage of this technique is that minimal sample preparation is required, and complementary information from nondestructive techniques such as FT-IR can be obtained on the same samples. In addition, a dedicated instrument is not required for particle analysis. This work establishes that ASAP-MS will be useful for identification of organic components of SOA in a variety of field and laboratory studies.

  17. Saharan Mineral Dust Experiment SAMUM 2006: Airborne observations of dust particle properties and vertical dust profiles

    NASA Astrophysics Data System (ADS)

    Petzold, A.; Weinzierl, B.; Esselborn, M.; Fiebig, M.; Fix, A.; Kiemle, C.; Wirth, M.; Müller, D.; Wendisch, M.; Schuetz, L.; Kandler, K.; Kahn, R.; Wagner, F.; Pereira, S.; Virkkula, A.

    2006-12-01

    The Saharan Mineral Dust Experiment (SAMUM) is an initiative of several German institutes. Its goal is the characterisation of optical, physical, chemical, and radiative properties of Saharan dust at the source region. SAMUM data may serve as ground truth data to validate satellite products and atmospheric transport models, and to support the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) mission. The first SAMUM intensive field phase was carried out in May/June 2006 in Southern Morocco. Ground sites were Ouarzazate (30.93° N, 6.9° W), Zagora (30.15° N, 5.37°), and Evora (38.53°N, 7.90°E) in Portugal for long- range transport studies. Research aircraft were operating from Ouarzazate (Partenavia, local flights) and Casablanca (DLR Falcon) at the Moroccan west coast As part of SAMUM, airborne measurements of dust particle properties were conducted using the German research aircraft Falcon. The DLR Falcon was equipped with an extensive set of aerosol physico-chemical instruments for size, volatility, and absorption measurements, impactor sampling for chemical analyses and with a nadir-looking high spectral resolution lidar (HSRL) for measuring aerosol extinction at 532 nm, and aerosol backscatter and depolarisation at 532 nm and 1064 nm. The field sites were equipped with aerosol sampling devices and instruments for particle size distribution measurements. During the SAMUM core phase, three large-scale dust events were probed which extended from southern Morocco to Portugal. Vertical (0 10 km) and horizontal (Saharan border to southern Portugal) dust plume structures, aerosol optical depth as well as particle microphysical and optical properties were studied for all cases. The upper boundary of the dust layers was found at altitudes between 4 and 6 km above sea level. The internal structure of the dust layers varied from well mixed to stratified. The influence of the Atlas Mountains on the lifting of the dust layers was monitored

  18. Induction of sister chromatid exchanges and bacterial revertants by organic extracts of airborne particles. [Humans

    SciTech Connect

    Lockard, J.M.; Viau, C.J.; Lee-Stephens, C.; Caldwell, J.C.; Wojciechowski, J.P.; Enoch, H.G.; Sabharwal, P.S.

    1981-01-01

    The genotoxicities of organic extracts of airborne particles have been studied extensively in the Salmonella/mammalian microsome (Ames) test, but in few other bioassays. In these studies, we tested benzene-acetone extracts of particulate pollutants collected in Lexington, Kentucky, for capacity to induce increases in sister chromatid exchanges (SCE) in human lumphocytes and V79 cells, as well as in the Ames assay. Extracts induced linear dose-related increases in SCE in human lumphocytes and in bacterial revertants.However, variable responses were observed in SCE assays in V79 cells with and without activation by rat liver S9 or feeder layers of irradiated Syrian hamster fetal cells. We conclude that the SCE assay in human lumphocytes may be a useful indicator of the potential risks to humans of airborne particulate pollutants, as it utilizes human cells recently taken from the host, is rapid and economical, and requires small quantities of test materials. However, thorough studies of the quantitative relationships between SCE induction and mutagenicity in human cells are needed.

  19. Testing and assessment of a large BGO detector for beach monitoring of radioactive particles

    NASA Astrophysics Data System (ADS)

    van der Graaf, E. R.; Rigollet, C.; Maleka, P. P.; Jones, D. G.

    2007-06-01

    The Beach Monitoring Steering Group (BMSG) was set up by UKAEA to explore whether improved systems for beach monitoring of radioactive particles are available. The BMSG commissioned the British Geological Survey (BGS) and the Nuclear Geophysics Division of the Kernfysisch Versneller Instituut (KVI/NGD), and other companies, to test their most sensitive system. This paper presents the results of trials in a specially created test facility at UKAEA Harwell with a large BGO detector. The detector's size and weight mean that it would be suitable for vehicle deployment but would be too large and heavy to carry in areas that could not be accessed by a vehicle. However, it would be possible to use the same methodology that is described here with a smaller detector capable of being carried in a backpack, albeit with reduced sensitivity for particle detection. The approach that we present is also applicable, with modifications, to the detection of offshore particles using a towed seabed detector.

  20. Release of airborne particles and Ag and Zn compounds from nanotechnology-enabled consumer sprays: Implications for inhalation exposure

    NASA Astrophysics Data System (ADS)

    Calderón, Leonardo; Han, Taewon T.; McGilvery, Catriona M.; Yang, Letao; Subramaniam, Prasad; Lee, Ki-Bum; Schwander, Stephan; Tetley, Teresa D.; Georgopoulos, Panos G.; Ryan, Mary; Porter, Alexandra E.; Smith, Rachel; Chung, Kian Fan; Lioy, Paul J.; Zhang, Junfeng; Mainelis, Gediminas

    2017-04-01

    The increasing prevalence and use of nanotechnology-enabled consumer products have increased potential consumer exposures to nanoparticles; however, there is still a lack of data characterizing such consumer exposure. The research reported here investigated near-field airborne exposures due to the use of 13 silver (Ag)-based and 5 zinc (Zn)-based consumer sprays. The products were sprayed into a specially designed glove box, and all products were applied with equal spraying duration and frequency. Size distribution and concentration of the released particles were assessed using a Scanning Mobility Particle Sizer and an Aerodynamic Particle Sizer. Inductively coupled plasma mass spectrometry (ICP-MS) was used to investigate the presence of metals in all investigated products. Spray liquids and airborne particles from select products were examined using transmission electron microscopy (TEM) and Energy Dispersive X-ray Spectroscopy (EDS). We found that all sprays produced airborne particles ranging in size from nano-sized particles (<100 nm) to coarse particles (>2.5 μm); however, there was a substantial variation in the released particle concentration depending on a product. The total aerosol mass concentration was dominated by the presence of coarse particles, and it ranged from ∼30 μg/m3 to ∼30,000 μg/m3. The TEM verified the presence of nanoparticles and their agglomerates in liquid and airborne states. The products were found to contain not only Ag and Zn compounds - as advertised on the product labeling - but also a variety of other metals including lithium, strontium, barium, lead, manganese and others. The results presented here can be used as input to model population exposures as well as form a basis for human health effects studies due to the use nanotechnology-enabled products.

  1. Concentrations and properties of airborne particles in the Mexico City subway system

    NASA Astrophysics Data System (ADS)

    Mugica-Álvarez, V.; Figueroa-Lara, J.; Romero-Romo, M.; Sepúlveda-Sánchez, J.; López-Moreno, T.

    2012-03-01

    Samples of PM10 and PM2.5 were collected using High Vol and MiniVol devices on the platform of a subway station in Mexico City and in an outdoor location close to it, using such devices. Soluble extractable organic matter (SEOM) and water solubility of metals were determined. Elemental composition and solubility of trace metals were determined and individual aerosol particles were studied with scanning electron microscopy (SEM) and energy dispersive X-ray spectrometry (EDX). The concentration levels in both sizes were similar during all days with the exception of weekends, especially on Sunday when activity decreases due to lower trains' frequency. The largest particles concentrations in the subway were found from 06:00 to 14:00 and the lowest concentrations were registered from 22:00 to 06:00. Concentrations of PM2.5 ranging between 60 μg m-3 and 93 μg m-3 (10% and 90% percentile) in the subway were 6% larger than outside, whereas PM10 were 20% larger than outside ranging from 88 μg m-3 to 145 μg m-3. Greater Fe, Cu, Ni, Cr and Mn concentrations were quantified in the subway samples as compared to the airborne particles by up to 2.5, 9, 1.8, 2.0 and 2.6 times, respectively. Even when the solubility percent of these metals in the subway PM was smaller than in the outdoor airborne particles, metals' concentrations were greater. SEM and EDS exhibit the presence of many individual particles with a large metal content in the subway samples. Correlation analysis showed the influence of outdoor PM in the subway aerosols, but characterization revealed also important differences in the presence of metals and SEOM, due to underground sources such as friction, brake system, and metals from sparking. This means that a large number of commuters are exposed during labor days to large toxic metals concentrations as they transit.

  2. Advances in Quantifying the Radiative Effects of Aerosol Particles on Climate from Airborne Field Studies

    NASA Astrophysics Data System (ADS)

    Pilewskie, P.; Schmidt, K. S.; Coddington, O.; Bergstrom, R.; Redemann, J.

    2007-12-01

    In the fourth assessment report of the Intergovernmental Panel on Climate Change, large uncertainties persist in estimates of climate forcing by aerosol particles. One contributor to this uncertainty is the poorly quantified vertical distribution of solar radiation absorbed by aerosol particles, from the regional to global scale. Another is the spectral and spatial variability of surface albedo, an effect that can dominate the top-of-atmosphere perturbations due to aerosol scattering and absorption, particularly over land. Over the past three years a number of intensive airborne field experiments (ICARTT, MILAGRO, GoMACCS) have contributed significantly to our understanding of the impact of pollution outflow from urban-industrial centers on radiative forcing, using spectrally resolved radiometric measurements and novel observationally-based methods to derive forcing efficiency and flux divergence. We present an overview of some of the most significant advances in direct radiative forcing realized by these studies, and recommendations on where the greatest challenges remain. In addition we present findings from these experiments on the influence of aerosol particles on cloud radiative properties, a potentially greater effect but even more uncertain than direct radiative forcing.

  3. Alternate particle removal technologies for the Airborne Activity Confinement System at the Savannah River Site

    SciTech Connect

    Brockmann, J.E.; Adkins, C.L.J.; Gelbard, F.

    1991-09-01

    This report presents a review of the filtration technologies available for the removal of particulate material from a gas stream. It was undertaken to identify alternate filtration technologies that may be employed in the Airborne Activity Confinement System (AACS) at the Savannah River Plant. This report is organized into six sections: (1) a discussion of the aerosol source term and its definition, (2) a short discussion of particle and gaseous contaminant removal mechanisms, (3) a brief overview of particle removal technologies, (4) a discussion of the existing AACS and its potential shortcomings, (5) an enumeration of issues to be addressed in upgrading the AACS, and, (6) a detailed discussion of the identified technologies. The purpose of this report is to identity available options to the existing particle removal system. This system is in continuous operation during routine operation of the reactor. As will be seen, there are a number of options and the selection of any technology or combination of technologies will depend on the design aerosol source term (yet to be appropriately defined) as well as the flow requirements and configuration. This report does not select a specific technology. It focuses on particulate removal and qualitatively on the removal of radio-iodine and mist elimination. Candidate technologies have been selected from industrial and nuclear gas cleaning applications.

  4. A new airborne sampler for interstitial particles in ice and liquid clouds

    NASA Astrophysics Data System (ADS)

    Moharreri, A.; Craig, L.; Rogers, D. C.; Brown, M.; Dhaniyala, S.

    2011-12-01

    In-situ measurements of cloud droplets and aerosols using aircraft platforms are required for understanding aerosol-cloud processes and aiding development of improved aerosol-cloud models. A variety of clouds with different temperature ranges and cloud particle sizes/phases must be studied for comprehensive knowledge about the role of aerosols in the formation and evolution of cloud systems under different atmospheric conditions. While representative aerosol measurements are regularly made from aircrafts under clear air conditions, aerosol measurements in clouds are often contaminated by the generation of secondary particles from the high speed impaction of ice particles and liquid droplets on the surfaces of the aircraft probes/inlets. A new interstitial particle sampler, called the blunt-body aerosol sampler (BASE) has been designed and used for aerosol sampling during two recent airborne campaigns using NCAR/NSF C-130 aircraft: PLOWS (2009-2010) and ICE-T (2011). Central to the design of the new interstitial inlet is an upstream blunt body housing that acts to shield/deflect large cloud droplets and ice particles from an aft sampling region. The blunt-body design also ensures that small shatter particles created from the impaction of cloud-droplets on the blunt-body are not present in the aft region where the interstitial inlet is located. Computational fluid dynamics (CFD) simulations along with particle transport modeling and wind tunnel studies have been utilized in different stages of design and development of this inlet. The initial flights tests during the PLOWS campaign showed that the inlet had satisfactory performance only in warm clouds and when large precipitation droplets were absent. In the presence of large droplets and ice, the inlet samples were contaminated with significant shatter artifacts. These initial results were reanalyzed in conjunction with a computational droplet shatter model and the numerical results were used to arrive at an

  5. Imaging of radioactive material and its host particle from the nuclear power plant accident in Japan by using imaging plate and electron microscopy

    NASA Astrophysics Data System (ADS)

    Adachi, Kouji; Zaizen, Yuji; Kimura, Tohru; Sakoh, Hiroshi; Igarashi, Yasuhito

    2013-04-01

    The Fukushima Daiichi Nuclear Power Plant accident in Japan on March, 2012, dispersed radioactive materials. In the Meteorological Research Institute, where locates 170 km south west from the power plant, we collected two types of filter aerosol samples and wet and dry deposition particles before and after the accident. Using these samples, we analyzed 1) radioactivity using an imaging plate (IP), which visualizes the radioactivity of samples in a two-dimensional plane with space resolution ~0.05 mm and 2) shape and compositions of particles that host radioactive materials using a scanning electron microscope (SEM) with energy-dispersive X-ray spectrometer (EDS). From the samples collected on March 15 and 21, we found radioactive spots on the filter samples using the IP, suggesting that radioactive materials, presumably Cs, were carried from the power plant. Radioactivity was also detected over the aggregates of dust particles in wet and dry deposition samples collected from March 2011. We did not find any detectable radioactive materials after the April when using the IP. We further investigated the radioactive spots using the SEM to identify the host particles of the radioactive materials and to detect radioactive materials from the EDS analysis. From the SEM analysis, we found that the particles on the filters include sulfate, mineral dust, and metals, but there were no particular particles or materials in the radioactive spots comparing to those in other area. The result suggests that the radioactive materials are hosted on the surface of other particles or inside them. We, so far, did not obtain any evidences that the radioactive materials are particulate with larger than 0.1 micro meter. Further analysis will need to identify the source of radioactive spots from individual particles using a manipulator as well as SEM and IP. Such studies will reveal where the radioactive materials exist in the environment, how they resuspend in the air, and how they could

  6. Monitoring of airborne biological particles in outdoor atmosphere. Part 1: Importance, variability and ratios.

    PubMed

    Núñez, Andrés; Amo de Paz, Guillermo; Rastrojo, Alberto; García, Ana M; Alcamí, Antonio; Gutiérrez-Bustillo, A Montserrat; Moreno, Diego A

    2016-03-01

    The first part of this review ("Monitoring of airborne biological particles in outdoor atmosphere. Part 1: Importance, variability and ratios") describes the current knowledge on the major biological particles present in the air regarding their global distribution, concentrations, ratios and influence of meteorological factors in an attempt to provide a framework for monitoring their biodiversity and variability in such a singular environment as the atmosphere. Viruses, bacteria, fungi, pollen and fragments thereof are the most abundant microscopic biological particles in the air outdoors. Some of them can cause allergy and severe diseases in humans, other animals and plants, with the subsequent economic impact. Despite the harsh conditions, they can be found from land and sea surfaces to beyond the troposphere and have been proposed to play a role also in weather conditions and climate change by acting as nucleation particles and inducing water vapour condensation. In regards to their global distribution, marine environments act mostly as a source for bacteria while continents additionally provide fungal and pollen elements. Within terrestrial environments, their abundances and diversity seem to be influenced by the land-use type (rural, urban, coastal) and their particularities. Temporal variability has been observed for all these organisms, mostly triggered by global changes in temperature, relative humidity, et cetera. Local fluctuations in meteorological factors may also result in pronounced changes in the airbiota. Although biological particles can be transported several hundreds of meters from the original source, and even intercontinentally, the time and final distance travelled are strongly influenced by factors such as wind speed and direction. [Int Microbiol 2016; 19(1):1-1 3].

  7. Radioactive Pollution Estimate for Fukushima Nuclear Power Plant by a Particle Model

    NASA Astrophysics Data System (ADS)

    Saito, Keisuke; Ogawa, Susumu

    2016-06-01

    On Mar 12, 2011, very wide radioactive pollution occurred by a hydrogen explosion in Fukushima Nuclear Power Plant. A large amount of radioisotopes started with four times of explosions. With traditional atmospheric diffusion models could not reconstruct radioactive pollution in Fukushima. Then, with a particle model, this accident was reconstructed from meteorological archive and Radar- AMeDAS. Calculations with the particle model were carried out for Mar 12, 15, 18 and 20 when east southeast winds blew for five hours continuously. Meteorological archive is expressed by wind speeds and directions in five-km grid every hour with eight classes of height till 3000 m. Radar- AMeDAS is precipitation data in one-km grid every thirty minutes. Particles are ten scales of 0.01 to 0.1 mm in diameter with specific weight of 2.65 and vertical speeds given by Stokes equation. But, on Mar 15, it rained from 16:30 and then the particles fell down at a moment as wet deposit in calculation. On the other hand, the altitudes on the ground were given by DEM with 1 km-grid. The spatial dose by emitted radioisotopes was referred to the observation data at monitoring posts of Tokyo Electric Power Company. The falling points of radioisotopes were expressed on the map using the particle model. As a result, the same distributions were obtained as the surface spatial dose of radioisotopes in aero-monitoring by Ministry of Education, Culture, Sports, Science and Technology. Especially, on Mar 15, the simulated pollution fitted to the observation, which extended to the northwest of Fukushima Daiichi Nuclear Power Plant and caused mainly sever pollution. By the particle model, the falling positions on the ground were estimated each particle size. Particles with more than 0.05 mm of size were affected by the topography and blocked by the mountains with the altitudes of more than 700 m. The particle model does not include the atmospheric stability, the source height, and deposit speeds. The

  8. Size-resolved source apportionment of airborne particle mass in a roadside environment.

    PubMed

    Riddle, Sarah G; Robert, Michael A; Jakober, Chris A; Hannigan, Michael P; Kleeman, Michael J

    2008-09-01

    Airborne particulate hopanes, steranes, and polycyclic aromatic hydrocarbons (PAHs) were measured in six size fractions < 1.8 microm particle diameter at one site upwind and two sites downwind of the Interstate 5 freeway in San Diego, CA. The smallest size fraction collected was exclusively in the ultrafine size range (D(p) < 0.1 microm; PM0.1). Size distributions of hopanes, steranes, and PAHs peaked between 0.10-0.18 microm particle aerodynamic diameter with a tail extending into the PM0.1 size range. This pattern is similar to previous dynamometer studies of hopane, sterane, and PAH size distributions emitted from gasoline- and diesel-powered vehicles. Size-resolved source profiles were combined to form an "on-road" profile for motor oil, diesel, and gasoline contributions to EC and OC. The resulting equations were used to predict source contributions to the size distributions of EC and OC in the roadside environment. The method successfully accounted for the majority of the carbonaceous material in particles with diameter < 0.18 microm, with significant residual material in larger size fractions. The peak in both the measured and predicted EC size distribution occurred between 0.1-0.18 microm particle aerodynamic diameter. The predicted OC size distribution peaked between 0.1-0.18 microm particle diameter, butthe measured OC size distribution peaked between 0.56-1.0 microm particle diameter, possibly because of secondary organic aerosol formation. Predicted OC concentrations in particles with diameter < 0.18 microm were greater than measured values 18 m downwind of the roadway but showed good agreement 37 m downwind. The largest source contributions to the PM0.1 and PM0.18 size fractions were different. PM0.18 was dominated by diesel fuel and motor oil combustion products while PM0.1 was dominated by diesel fuel and gasoline fuel combustion products. Total source contributions to ultrafine (PM0.1) EC concentrations 37 m downwind of the roadway were 44 +/- 6

  9. Airborne observations of new particle formation events in the boundary layer using a Zeppelin

    NASA Astrophysics Data System (ADS)

    Lampilahti, Janne; Manninen, Hanna E.; Nieminen, Tuomo; Mirme, Sander; Pullinen, Iida; Yli-Juuti, Taina; Schobesberger, Siegfried; Kangasluoma, Juha; Kontkanen, Jenni; Lehtipalo, Katrianne; Ehn, Mikael; Mentel, Thomas F.; Petäjä, Tuukka; Kulmala, Markku

    2014-05-01

    Atmospheric new particle formation (NPF) is a frequent and ubiquitous process in the atmosphere and a major source of newly formed aerosol particles [1]. However, it is still unclear how the aerosol particle distribution evolves in space and time during an NPF. We investigated where in the planetary boundary layer does NPF begin and how does the aerosol number size distribution develop in space and time during it. We measured in Hyytiälä, southern Finland using ground based and airborne measurements. The measurements were part of the PEGASOS project. NPF was studied on six scientific flights during spring 2013 using a Zeppelin NT class airship. Ground based measurements were simultaneously conducted at SMEAR II station located in Hyytiälä. The flight profiles over Hyytiälä were flown between sunrise and noon during the growth of the boundary layer. The profiles over Hyytiälä covered vertically a distance of 100-1000 meters reaching the mixed layer, stable (nocturnal) boundary layer and the residual layer. Horizontally the profiles covered approximately a circular area of four kilometers in diameter. The measurements include particle number size distribution by Neutral cluster and Air Ion Spectrometer (NAIS), Differential Mobility Particle Sizer (DMPS) and Particle Size Magnifier (PSM) [2], meteorological parameters and position (latitude, longitude and altitude) of the Zeppelin. Beginning of NPF was determined from an increase in 1.7-3 nm ion concentration. Height of the mixed layer was estimated from relative humidity measured on-board the Zeppelin. Particle growth rate during NPF was calculated. Spatial inhomogeneities in particle number size distribution during NPF were located and the birthplace of the particles was estimated using the growth rate and trajectories. We observed a regional NPF event that began simultaneously and evolved uniformly inside the mixed layer. In the horizontal direction we observed a long and narrow high concentration plume of

  10. Correlation between polycyclic aromatic hydrocarbons concentration and airborne particle mutagenicity in the rubber factory.

    PubMed

    Barański, B; Palus, J; Rogaczewska, T; Szymczak, W; Spiechowicz, E

    1992-01-01

    The study was undertaken to evaluate the correlation between benzo[a]pyrene and coal tar pitch volatiles concentrations and mutagenic activity of airborne particles sampled at different workplaces of the factory producing various types of tires. The solid phase of aerosols was collected on Whatman glass-fibers filters using Staplex pumps. Coal tar pitch volatiles (CTPVs) were extracted from sample filters using ultrasonic-benzene extraction and determined by the gravimetric method. Benzo[a]pyrene (BaP) analysis was performed using high performance liquid chromatography with a spectrofluorimetric detector. The mutagenic substances were extracted from collected material with acetone. The mutagenic properties were estimated with the Ames' test using S. typhimurium strain TA98 without and with S9 fraction. At nearly all workplaces the concentrations of BaP and CTPVs were within the range of 4-61 ng/m3 and 0.11-1.26 mg/m3, respectively. Only at weighing were they much higher and amounted to 172-2261 ng/m3 for BaP and 3.05-4.07 mg/m3 for CTPVs. The highest exposure to mutagenic airborne particulate matter was found at weighing (1500 rev/m3), the mixers loading level (> 500 rev/m3) and the carbon black station (> 150 rev/m3). The air mutagenic activity at other workplaces, especially at the extruder mill of the mixer (> 90 rev/m3), the two-roll mill of mixers (> 70 rev/m3), mixer I loading (> 70 rev/m3), calendering (> 70 rev/m3) and fender vulcanizing (> 80 rev/m3) was even much more higher than that found in the urban indoor and outdoor air (2-9 rev/m3).(ABSTRACT TRUNCATED AT 250 WORDS)

  11. Exposure vs toxicity levels of airborne quartz, metal and carbon particles in cast iron foundries.

    PubMed

    Moroni, Beatrice; Viti, Cecilia; Cappelletti, David

    2014-01-01

    Aerosol dust samples and quartz raw materials from different working stations in foundry plants were characterized in order to assess the health risk in this working environment. Samples were analysed by scanning and transmission electron microscopy coupled with image analysis and microanalysis, and by cathodoluminescence spectroscopy. In addition, the concentration and the solubility degree of Fe and other metals of potential health effect (Mn, Zn and Pb) in the bulk samples were determined by inductively coupled plasma atomic emission spectrometry (ICP-AES). Overall, the results indicate substantial changes in quartz crystal structure and texture when passing from the raw material to the airborne dust, which include lattice defects, non-bridging oxygen hole centres and contamination of quartz grains by metal and/or graphite particles. All these aspects point towards the relevance of surface properties on reactivity. Exposure doses have been estimated based on surface area, and compared with threshold levels resulting from toxicology. The possible synergistic effects of concomitant exposure to inhalable magnetite, quartz and/or graphite particles in the same working environment have been properly remarked.

  12. Comparison of Size and Geography of Airborne Tungsten Particles in Fallon, Nevada, and Sweet Home, Oregon, with Implications for Public Health

    PubMed Central

    Sheppard, Paul R.; Bierman, Brian J.; Rhodes, Kent; Ridenour, Gary; Witten, Mark L.

    2012-01-01

    To improve understanding of possible connections between airborne tungsten and public health, size and geography of airborne tungsten particles collected in Fallon, Nevada, and Sweet Home, Oregon, were compared. Both towns have industrial tungsten facilities, but only Fallon has experienced a cluster of childhood leukemia. Fallon and Sweet Home are similar to one another by their particles of airborne tungsten being generally small in size. Meteorologically, much, if not most, of residential Fallon is downwind of its hard metal facility for at least some fraction of time at the annual scale, whereas little of residential Sweet Home is downwind of its tungsten facility. Geographically, most Fallon residents potentially spend time daily within an environment containing elevated levels of airborne tungsten. In contrast, few Sweet Home residents potentially spend time daily within an airborne environment with elevated levels of airborne tungsten. Although it cannot be concluded from environmental data alone that elevated airborne tungsten causes childhood leukemia, the lack of excessive cancer in Sweet Home cannot logically be used to dismiss the possibility of airborne tungsten as a factor in the cluster of childhood leukemia in Fallon. Detailed modeling of all variables affecting airborne loadings of heavy metals would be needed to legitimately compare human exposures to airborne tungsten in Fallon and Sweet Home. PMID:22523506

  13. Comparison of size and geography of airborne tungsten particles in Fallon, Nevada, and Sweet Home, Oregon, with implications for public health.

    PubMed

    Sheppard, Paul R; Bierman, Brian J; Rhodes, Kent; Ridenour, Gary; Witten, Mark L

    2012-01-01

    To improve understanding of possible connections between airborne tungsten and public health, size and geography of airborne tungsten particles collected in Fallon, Nevada, and Sweet Home, Oregon, were compared. Both towns have industrial tungsten facilities, but only Fallon has experienced a cluster of childhood leukemia. Fallon and Sweet Home are similar to one another by their particles of airborne tungsten being generally small in size. Meteorologically, much, if not most, of residential Fallon is downwind of its hard metal facility for at least some fraction of time at the annual scale, whereas little of residential Sweet Home is downwind of its tungsten facility. Geographically, most Fallon residents potentially spend time daily within an environment containing elevated levels of airborne tungsten. In contrast, few Sweet Home residents potentially spend time daily within an airborne environment with elevated levels of airborne tungsten. Although it cannot be concluded from environmental data alone that elevated airborne tungsten causes childhood leukemia, the lack of excessive cancer in Sweet Home cannot logically be used to dismiss the possibility of airborne tungsten as a factor in the cluster of childhood leukemia in Fallon. Detailed modeling of all variables affecting airborne loadings of heavy metals would be needed to legitimately compare human exposures to airborne tungsten in Fallon and Sweet Home.

  14. Detection of radioactive particles offshore by γ-ray spectrometry Part I: Monte Carlo assessment of detection depth limits

    NASA Astrophysics Data System (ADS)

    Maučec, M.; de Meijer, R. J.; Rigollet, C.; Hendriks, P. H. G. M.; Jones, D. G.

    2004-06-01

    A joint research project between the British Geological Survey and Nuclear Geophysics Division of the Kernfysisch Versneller Instituut, Groningen, the Netherlands, was commissioned by the United Kingdom Atomic Energy Authority to establish the efficiency of a towed seabed γ-ray spectrometer for the detection of 137Cs-containing radioactive particles offshore Dounreay, Scotland. Using the MCNP code, a comprehensive Monte Carlo feasibility study was carried out to model various combinations of geological matrices, particle burial depth and lateral displacement, source activity and detector material. To validate the sampling and absolute normalisation procedures of MCNP for geometries including multiple (natural and induced) heterogeneous sources in environmental monitoring, a benchmark experiment was conducted. The study demonstrates the ability of seabed γ-ray spectrometry to locate radioactive particles offshore and to distinguish between γ count rate increases due to particles from those due to enhanced natural radioactivity. The information presented in this study will be beneficial for estimation of the inventory of 137Cs particles and their activity distribution and for the recovery of particles from the sea floor. In this paper, the Monte Carlo assessment of the detection limits is presented. The estimation of the required towing speed and acquisition times and their application to radioactive particle detection and discrimination offshore formed a supplementary part of this study.

  15. Airborne particles of the california central valley alter the lungs of healthy adult rats.

    PubMed Central

    Smith, Kevin R; Kim, Seongheon; Recendez, Julian J; Teague, Stephen V; Ménache, Margaret G; Grubbs, David E; Sioutas, Constantinos; Pinkerton, Kent E

    2003-01-01

    Epidemiologic studies have shown that airborne particulate matter (PM) with a mass median aerodynamic diameter < 10 microm (PM10) is associated with an increase in respiratory-related disease. However, there is a growing consensus that particles < 2.5 microm (PM2.5), including many in the ultrafine (< 0.1 microm) size range, may elicit greater adverse effects. PM is a complex mixture of organic and inorganic compounds; however, those components or properties responsible for biologic effects on the respiratory system have yet to be determined. During the fall and winter of 2000-2001, healthy adult Sprague-Dawley rats were exposed in six separate experiments to filtered air or combined fine (PM2.5) and ultrafine portions of ambient PM in Fresno, California, enhanced approximately 20-fold above outdoor levels. The intent of these studies was to determine if concentrated fine/ultrafine fractions of PM are cytotoxic and/or proinflammatory in the lungs of healthy adult rats. Exposures were for 4 hr/day for 3 consecutive days. The mean mass concentration of particles ranged from 190 to 847 microg/m3. PM was enriched primarily with ammonium nitrate, organic and elemental carbon, and metals. Viability of cells recovered by bronchoalveolar lavage (BAL) from rats exposed to concentrated PM was significantly decreased during 4 of 6 weeks, compared with rats exposed to filtered air (p< 0.05). Total numbers of BAL cells were increased during 1 week, and neutrophil numbers were increased during 2 weeks. These observations strongly suggest exposure to enhanced concentrations of ambient fine/ultrafine particles in Fresno is associated with mild, but significant, cellular effects in the lungs of healthy adult rats. PMID:12782490

  16. MEMS-based silicon cantilevers with integrated electrothermal heaters for airborne ultrafine particle sensing

    NASA Astrophysics Data System (ADS)

    Wasisto, Hutomo Suryo; Merzsch, Stephan; Waag, Andreas; Peiner, Erwin

    2013-05-01

    The development of low-cost and low-power MEMS-based cantilever sensors for possible application in hand-held airborne ultrafine particle monitors is described in this work. The proposed resonant sensors are realized by silicon bulk micromachining technology with electrothermal excitation, piezoresistive frequency readout, and electrostatic particle collection elements integrated and constructed in the same sensor fabrication process step of boron diffusion. Built-in heating resistor and full Wheatstone bridge are set close to the cantilever clamp end for effective excitation and sensing, respectively, of beam deflection. Meanwhile, the particle collection electrode is located at the cantilever free end. A 300 μm-thick, phosphorus-doped silicon bulk wafer is used instead of silicon-on-insulator (SOI) as the starting material for the sensors to reduce the fabrication costs. To etch and release the cantilevers from the substrate, inductively coupled plasma (ICP) cryogenic dry etching is utilized. By controlling the etching parameters (e.g., temperature, oxygen content, and duration), cantilever structures with thicknesses down to 10 - 20 μm are yielded. In the sensor characterization, the heating resistor is heated and generating thermal waves which induce thermal expansion and further cause mechanical bending strain in the out-of-plane direction. A resonant frequency of 114.08 +/- 0.04 kHz and a quality factor of 1302 +/- 267 are measured in air for a fabricated rectangular cantilever (500x100x13.5 μm3). Owing to its low power consumption of a few milliwatts, this electrothermal cantilever is suitable for replacing the current external piezoelectric stack actuator in the next generation of the miniaturized cantilever-based nanoparticle detector (CANTOR).

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

    SciTech Connect

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

    1996-12-31

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

  18. What We are Learning about Airborne Particles from MISR Multi-angle Imaging

    NASA Astrophysics Data System (ADS)

    Kahn, Ralph

    The NASA Earth Observing System’s Multi-angle Imaging SpectroRadiometer (MISR) instrument has been collecting global observations in 36 angular-spectral channels about once per week for over 14 years. Regarding airborne particles, MISR is contributing in three broad areas: (1) aerosol optical depth (AOD), especially over land surface, including bright desert, (2) wildfire smoke, desert dust, and volcanic ash injection and near-source plume height, and (3) aerosol type, the aggregate of qualitative constraints on particle size, shape, and single-scattering albedo (SSA). Early advances in the retrieval of these quantities focused on AOD, for which surface-based sun photometers provided a global network of ground truth, and plume height, for which ground-based and airborne lidar offered near-coincident validation data. MSIR monthly, global AOD products contributed directly to the advances in modeling aerosol impacts on climate made between the Inter-governmental Panel on Climate Change (IPCC) third and fourth assessment reports. MISR stereo-derived plume heights are now being used to constrain source inventories for the AeroCom aerosol-climate modeling effort. The remaining challenge for the MISR aerosol effort is to refine and validate our global aerosol type product. Unlike AOD and plume height, aerosol type as retrieved by MISR is a qualitative classification derived from multi-dimensional constraints, so evaluation must be done on a categorical basis. Coincident aerosol type validation data are far less common than for AOD, and, except for rare Golden Days during aircraft field campaigns, amount to remote sensing retrievals from suborbital instruments having uncertainties comparable to those from the MISR product itself. And satellite remote sensing retrievals of aerosol type are much more sensitive to scene conditions such as surface variability and AOD than either AOD or plume height. MISR aerosol type retrieval capability and information content have been

  19. Hybrid dynamic radioactive particle tracking (RPT) calibration technique for multiphase flow systems

    NASA Astrophysics Data System (ADS)

    Khane, Vaibhav; Al-Dahhan, Muthanna H.

    2017-04-01

    The radioactive particle tracking (RPT) technique has been utilized to measure three-dimensional hydrodynamic parameters for multiphase flow systems. An analytical solution to the inverse problem of the RPT technique, i.e. finding the instantaneous tracer positions based upon instantaneous counts received in the detectors, is not possible. Therefore, a calibration to obtain a counts-distance map is needed. There are major shortcomings in the conventional RPT calibration method due to which it has limited applicability in practical applications. In this work, the design and development of a novel dynamic RPT calibration technique are carried out to overcome the shortcomings of the conventional RPT calibration method. The dynamic RPT calibration technique has been implemented around a test reactor with 1foot in diameter and 1 foot in height using Cobalt-60 as an isotopes tracer particle. Two sets of experiments have been carried out to test the capability of novel dynamic RPT calibration. In the first set of experiments, a manual calibration apparatus has been used to hold a tracer particle at known static locations. In the second set of experiments, the tracer particle was moved vertically downwards along a straight line path in a controlled manner. The obtained reconstruction results about the tracer particle position were compared with the actual known position and the reconstruction errors were estimated. The obtained results revealed that the dynamic RPT calibration technique is capable of identifying tracer particle positions with a reconstruction error between 1 to 5.9 mm for the conditions studied which could be improved depending on various factors outlined here.

  20. Iron speciation of airborne subway particles by the combined use of energy dispersive electron probe X-ray microanalysis and Raman microspectrometry.

    PubMed

    Eom, Hyo-Jin; Jung, Hae-Jin; Sobanska, Sophie; Chung, Sang-Gwi; Son, Youn-Suk; Kim, Jo-Chun; Sunwoo, Young; Ro, Chul-Un

    2013-11-05

    Quantitative energy-dispersive electron probe X-ray microanalysis (ED-EPMA), known as low-Z particle EPMA, and Raman microspectrometry (RMS) were applied in combination for an analysis of the iron species in airborne PM10 particles collected in underground subway tunnels. Iron species have been reported to be a major chemical species in underground subway particles generated mainly from mechanical wear and friction processes. In particular, iron-containing particles in subway tunnels are expected to be generated with minimal outdoor influence on the particle composition. Because iron-containing particles have different toxicity and magnetic properties depending on their oxidation states, it is important to determine the iron species of underground subway particles in the context of both indoor public health and control measures. A recently developed analytical methodology, i.e., the combined use of low-Z particle EPMA and RMS, was used to identify the chemical species of the same individual subway particles on a single particle basis, and the bulk iron compositions of airborne subway particles were also analyzed by X-ray diffraction. The majority of airborne subway particles collected in the underground tunnels were found to be magnetite, hematite, and iron metal. All the particles collected in the tunnels of underground subway stations were attracted to permanent magnets due mainly to the almost ubiquitous ferrimagnetic magnetite, indicating that airborne subway particles can be removed using magnets as a control measure.

  1. Beryllium solubility in occupational airborne particles: Sequential extraction procedure and workplace application.

    PubMed

    Rousset, Davy; Durand, Thibaut

    2016-01-01

    Modification of an existing sequential extraction procedure for inorganic beryllium species in the particulate matter of emissions and in working areas is described. The speciation protocol was adapted to carry out beryllium extraction in closed-face cassette sampler to take wall deposits into account. This four-step sequential extraction procedure aims to separate beryllium salts, metal, and oxides from airborne particles for individual quantification. Characterization of the beryllium species according to their solubility in air samples may provide information relative to toxicity, which is potentially related to the different beryllium chemical forms. Beryllium salts (BeF(2), BeSO(4)), metallic beryllium (Bemet), and beryllium oxide (BeO) were first individually tested, and then tested in mixtures. Cassettes were spiked with these species and recovery rates were calculated. Quantitative analyses with matched matrix were performed using inductively coupled plasma mass spectrometry (ICP-MS). Method Detection Limits (MDLs) were calculated for the four matrices used in the different extraction steps. In all cases, the MDL was below 4.2 ng/sample. This method is appropriate for assessing occupational exposure to beryllium as the lowest recommended threshold limit values are 0.01 µg.m(-3) in France([) (1) (]) and 0.05 µg.m(-3) in the USA.([ 2 ]) The protocol was then tested on samples from French factories where occupational beryllium exposure was suspected. Beryllium solubility was variable between factories and among the same workplace between different tasks.

  2. Development of Labview based data acquisition and multichannel analyzer software for radioactive particle tracking system

    SciTech Connect

    Rahman, Nur Aira Abd Yussup, Nolida; Ibrahim, Maslina Bt. Mohd; Abdullah, Nor Arymaswati; Mokhtar, Mukhlis B.; Abdullah, Jaafar B.; Hassan, Hearie B.

    2015-04-29

    A DAQ (data acquisition) software called RPTv2.0 has been developed for Radioactive Particle Tracking System in Malaysian Nuclear Agency. RPTv2.0 that features scanning control GUI, data acquisition from 12-channel counter via RS-232 interface, and multichannel analyzer (MCA). This software is fully developed on National Instruments Labview 8.6 platform. Ludlum Model 4612 Counter is used to count the signals from the scintillation detectors while a host computer is used to send control parameters, acquire and display data, and compute results. Each detector channel consists of independent high voltage control, threshold or sensitivity value and window settings. The counter is configured with a host board and twelve slave boards. The host board collects the counts from each slave board and communicates with the computer via RS-232 data interface.

  3. Assessing inhalation exposure from airborne soil contaminants

    SciTech Connect

    Shinn, J.H.

    1998-04-01

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

  4. The assessment of doses and effects from intakes of radioactive particles.

    PubMed Central

    Harrison, J D; Stather, J W

    1996-01-01

    The behaviour of radionuclides after entry into the body and the radiation doses received by individual tissues depend on the chemical nature of the element, the physicochemical form of the intake, the radioactive half-life of the isotope and the type and energy of the emissions. Ingestion of radionuclides in insoluble particles will result in radiation doses being delivered to tissues of the gastrointestinal (GI) tract; other tissues will also be irradiated by nuclides with penetrating photons emissions (gamma) but doses may be largely confined to the GI tract for charged particle emissions (alpha, beta). Ingestion of more soluble forms will lead to greater absorption to blood and deposition in other tissues and therefore may result in greater doses to other tissues. Similar considerations apply to inhaled material and to the entry of radionuclides through cuts or wounds. For ingested materials, including particles, more information is needed on uptake and retention in intestinal tissues and consequent doses to sensitive cells, particularly for alpha emitters. There has been concern that the pattern of distribution of activity throughout irradiated tissues may influence the extent of damage, particularly for alpha emitters because of the localised deposition of energy and their greater relative biological effectiveness compared with beta/gamma emitters. Aggregation of activity has the potential to result in greater acute tissue damage and has been shown, for example, to result in focalised pneumonitis and fibrosis in the lung and ulceration of the skin. The main long-term effect of irradiation of tissues is the induction of malignant change, although hereditary disease may also be of concern following irradiation of the gonads. There are only limited data available to compare the effect on cancer induction of heterogeneous and homogeneous irradiation of tissues. However, the available information, for irradiation of the lung, skin or liver, indicates that in

  5. Characterizing the impact of urban emissions on regional aerosol particles; airborne measurements during the MEGAPOLI experiment

    NASA Astrophysics Data System (ADS)

    Freney, E. J.; Sellegri, K.; Canonaco, F.; Colomb, A.; Borbon, A.; Michoud, V.; Doussin, J.-F.; Crumeyrolle, S.; Amarouch, N.; Pichon, J.-M.; Prévôt, A. S. H.; Beekmann, M.; Schwarzenböeck, A.

    2013-09-01

    The MEGAPOLI experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS) giving detailed information of the non-refractory submicron aerosol species. The mass concentration of BC, measured by a particle absorption soot photometer (PSAP), was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA), black carbon and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NOx. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (-log(NOx / NOy). Plotting the equivalent ratios for the Positive Matrix Factorization (PMF) resolved species (LV-OOA, SV-OOA, and HOA) illustrate that the increase in OA is a result of secondary organic aerosol (SOA). Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in Mexico city, Mexico and in New England, USA. Using the measured VOCs species together with recent organic aerosol formation yields we predicted ~ 50% of the measured organics. These airborne measurements during the MEGAPOLI experiment show that urban emissions contribute to the formation of OA

  6. Characterizing the impact of urban emissions on regional aerosol particles: airborne measurements during the MEGAPOLI experiment

    NASA Astrophysics Data System (ADS)

    Freney, E. J.; Sellegri, K.; Canonaco, F.; Colomb, A.; Borbon, A.; Michoud, V.; Doussin, J.-F.; Crumeyrolle, S.; Amarouche, N.; Pichon, J.-M.; Bourianne, T.; Gomes, L.; Prevot, A. S. H.; Beekmann, M.; Schwarzenböeck, A.

    2014-02-01

    The MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris, using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS), giving detailed information on the non-refractory submicron aerosol species. The mass concentration of black carbon (BC), measured by a particle absorption soot photometer (PSAP), was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA), BC, and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NOx. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (-log(NOx / NOy)). Plotting the equivalent ratios of different organic aerosol species (LV-OOA, SV-OOA, and HOA) illustrate that the increase in OA is a result of secondary organic aerosol (SOA) formation. Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in London, Mexico City, and in New England, USA. Using the measured SOA volatile organic compounds (VOCs) species together with organic aerosol formation

  7. Utilization of airborne gamma ray spectrometric data for geological mapping, radioactive mineral exploration and environmental monitoring of southeastern Aswan city, South Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Youssef, Mohamed A. S.; Elkhodary, Shadia T.

    2013-12-01

    The present work utilizes airborne gamma ray spectrometric data in a trial to refine surface geology of igneous, metamorphic and sedimentary rocks, detect any radioactive mineralization and monitor environment at southeastern Aswan city, South Eastern Desert, Egypt. This area is mainly covered with igneous rocks (younger granites, older granites, metasediments, metavolcanics, metagabbro, Tertiary basalt and ring complex), metamorphic rocks as well as sedimentary rocks (Um Barmil Formation, Timsah Formation, Abu Aggag Formation and wadi sediments). Airborne gamma ray spectrometry can be very helpful in mapping surface geology. This provides estimates of the apparent surface concentrations of the most common naturally occurring radioactive elements, such as potassium (K), equivalent uranium (eU) and equivalent thorium (eTh). This is based on the assumption that, the absolute and relative concentrations of these radioelements vary measurably and significantly with lithology. The composite image technique is used to display simultaneously three parameters of the three radioelement concentrations and their three binary ratios on one image. The technique offers much in terms of lithological discrimination, based on colour differences and showed efficiency in defining areas, where different lithofacies occur within areas mapped as one continuous lithology. The integration between surface geological information and geophysical data led to detailing the surface geology and the contacts between different rock units. Significant locations or favourable areas for uranium exploration are defined, where the measurements exceed (X + 2S), taking X as the arithmetic mean of eU, eU/eTh and eU/K measurements and S as the standard deviation corresponding to each variables. The study area shows the presence of four relatively high uraniferous zones. These zones cannot be ignored and need further ground follow-up. In addition, the trend analysis based on the three radioelement maps and

  8. RADIOACTIVE POSITRON EMITTER PRODUCTION BY ENERGETIC ALPHA PARTICLES IN SOLAR FLARES

    SciTech Connect

    Murphy, R. J.; Kozlovsky, B.; Share, G. H. E-mail: benz@wise.tau.ac.il

    2015-01-01

    Measurements of the 0.511 MeV positron-annihilation line from solar flares are used to explore the flare process in general and ion acceleration in particular. In flares, positrons are produced primarily by the decay of radioactive positron-emitting isotopes resulting from nuclear interactions of flare-accelerated ions with ambient solar material. Kozlovsky et al. provided ion-energy-dependent production cross sections for 67 positron emitters evaluated from their threshold energies (some <1 MeV nucleon{sup –1}) to a GeV nucleon{sup –1}, incorporating them into a computer code for calculating positron-emitter production. Adequate cross-section measurements were available for proton reactions, but not for α-particle reactions where only crude estimates were possible. Here we re-evaluate the α-particle cross sections using new measurements and nuclear reaction codes. In typical large gamma-ray line flares, proton reactions dominate positron production, but α-particle reactions will dominate for steeper accelerated-ion spectra because of their relatively low threshold energies. With the accelerated-{sup 3}He reactions added previously, the code is now reliable for calculating positron production from any distribution of accelerated-ion energies, not just those of typical flares. We have made the code available in the online version of the Journal. We investigate which reactions, projectiles, and ion energies contribute to positron production. We calculate ratios of the annihilation-line fluence to fluences of other gamma-ray lines. Such ratios can be used in interpreting flare data and in determining which nuclear radiation is most sensitive for revealing acceleration of low-energy ions at the Sun.

  9. Source apportionment of airborne particles in commercial aircraft cabin environment: Contributions from outside and inside of cabin

    NASA Astrophysics Data System (ADS)

    Li, Zheng; Guan, Jun; Yang, Xudong; Lin, Chao-Hsin

    2014-06-01

    Airborne particles are an important type of air pollutants in aircraft cabin. Finding sources of particles is conducive to taking appropriate measures to remove them. In this study, measurements of concentration and size distribution of particles larger than 0.3 μm (PM>0.3) were made on nine short haul flights from September 2012 to March 2013. Particle counts in supply air and breathing zone air were both obtained. Results indicate that the number concentrations of particles ranged from 3.6 × 102 counts L-1 to 1.2 × 105 counts L-1 in supply air and breathing zone air, and they first decreased and then increased in general during the flight duration. Peaks of particle concentration were found at climbing, descending, and cruising phases in several flights. Percentages of particle concentration in breathing zone contributed by the bleed air (originated from outside) and cabin interior sources were calculated. The bleed air ratios, outside airflow rates and total airflow rates were calculated by using carbon dioxide as a ventilation tracer in five of the nine flights. The calculated results indicate that PM>0.3 in breathing zone mainly came from unfiltered bleed air, especially for particle sizes from 0.3 to 2.0 μm. And for particles larger than 2.0 μm, contributions from the bleed air and cabin interior were both important. The results would be useful for developing better cabin air quality control strategies.

  10. Particle size analysis of radioactive aerosols formed by irradiation of argon using 65 MeV quasi-monoenergetic neutrons.

    PubMed

    Endo, A; Noguchi, H; Tanaka, Su; Kanda, Y; Oki, Y; Iida, T; Sato, K; Tsuda, S

    2002-04-01

    The size distributions of 38Cl and 39Cl aerosols formed from the irradiation of argon gas containing di-octyl phthalate (DOP) aerosols by 65 MeV quasi-monoenergetic neutrons were measured to study the formation mechanism of radioactive aerosols in high-energy radiation fields. Both the number size distribution and the activity-weighted size distribution were measured using an electrical low-pressure impactor. It was found that the 35Cl and 39Cl aerosols are formed by attachment of the radioactive atoms generated by the neutron-induced reaction to the DOP aerosol particles.

  11. Nanoscale characterization of PM2.5 airborne pollutants reveals high adhesiveness and aggregation capability of soot particles

    PubMed Central

    Shi, Yuanyuan; Ji, Yanfeng; Sun, Hui; Hui, Fei; Hu, Jianchen; Wu, Yaxi; Fang, Jianlong; Lin, Hao; Wang, Jianxiang; Duan, Huiling; Lanza, Mario

    2015-01-01

    In 2012 air pollutants were responsible of seven million human death worldwide, and among them particulate matter with an aerodynamic diameter of 2.5 micrometers or less (PM2.5) are the most hazardous because they are small enough to invade even the smallest airways and penetrate to the lungs. During the last decade the size, shape, composition, sources and effect of these particles on human health have been studied. However, the noxiousness of these particles not only relies on their chemical toxicity, but particle morphology and mechanical properties affect their thermodynamic behavior, which has notable impact on their biological activity. Therefore, correlating the physical, mechanical and chemical properties of PM2.5 airborne pollutants should be the first step to characterize their interaction with other bodies but, unfortunately, such analysis has never been reported before. In this work, we present the first nanomechanical characterization of the most abundant and universal groups of PM2.5 airborne pollutants and, by means of atomic force microscope (AFM) combined with other characterization tools, we observe that fluffy soot aggregates are the most sticky and unstable. Our experiments demonstrate that such particles show strong adhesiveness and aggregation, leading to a more diverse composition and compiling all possible toxic chemicals. PMID:26177695

  12. Nanoscale characterization of PM2.5 airborne pollutants reveals high adhesiveness and aggregation capability of soot particles.

    PubMed

    Shi, Yuanyuan; Ji, Yanfeng; Sun, Hui; Hui, Fei; Hu, Jianchen; Wu, Yaxi; Fang, Jianlong; Lin, Hao; Wang, Jianxiang; Duan, Huiling; Lanza, Mario

    2015-07-16

    In 2012 air pollutants were responsible of seven million human death worldwide, and among them particulate matter with an aerodynamic diameter of 2.5 micrometers or less (PM2.5) are the most hazardous because they are small enough to invade even the smallest airways and penetrate to the lungs. During the last decade the size, shape, composition, sources and effect of these particles on human health have been studied. However, the noxiousness of these particles not only relies on their chemical toxicity, but particle morphology and mechanical properties affect their thermodynamic behavior, which has notable impact on their biological activity. Therefore, correlating the physical, mechanical and chemical properties of PM2.5 airborne pollutants should be the first step to characterize their interaction with other bodies but, unfortunately, such analysis has never been reported before. In this work, we present the first nanomechanical characterization of the most abundant and universal groups of PM2.5 airborne pollutants and, by means of atomic force microscope (AFM) combined with other characterization tools, we observe that fluffy soot aggregates are the most sticky and unstable. Our experiments demonstrate that such particles show strong adhesiveness and aggregation, leading to a more diverse composition and compiling all possible toxic chemicals.

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

    PubMed

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

    2012-04-30

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

  14. Airborne particle emission of a commercial 3D printer: the effect of filament material and printing temperature.

    PubMed

    Stabile, L; Scungio, M; Buonanno, G; Arpino, F; Ficco, G

    2017-03-01

    The knowledge of exposure to the airborne particle emitted from three-dimensional (3D) printing activities is becoming a crucial issue due to the relevant spreading of such devices in recent years. To this end, a low-cost desktop 3D printer based on fused deposition modeling (FDM) principle was used. Particle number, alveolar-deposited surface area, and mass concentrations were measured continuously during printing processes to evaluate particle emission rates (ERs) and factors. Particle number distribution measurements were also performed to characterize the size of the emitted particles. Ten different materials and different extrusion temperatures were considered in the survey. Results showed that all the investigated materials emit particles in the ultrafine range (with a mode in the 10-30-nm range), whereas no emission of super-micron particles was detected for all the materials under investigation. The emission was affected strongly by the extrusion temperature. In fact, the ERs increase as the extrusion temperature increases. Emission rates up to 1×10(12)  particles min(-1) were calculated. Such high ERs were estimated to cause large alveolar surface area dose in workers when 3D activities run. In fact, a 40-min-long 3D printing was found to cause doses up to 200 mm(2) .

  15. Airborne instruments to measure atmospheric aerosol particles, clouds and radiation: A cook's tour of mature and emerging technology

    NASA Astrophysics Data System (ADS)

    Baumgardner, D.; Brenguier, J. L.; Bucholtz, A.; Coe, H.; DeMott, P.; Garrett, T. J.; Gayet, J. F.; Hermann, M.; Heymsfield, A.; Korolev, A.; Krämer, M.; Petzold, A.; Strapp, W.; Pilewskie, P.; Taylor, J.; Twohy, C.; Wendisch, M.; Bachalo, W.; Chuang, P.

    2011-10-01

    An overview is presented of airborne systems for in situ measurements of aerosol particles, clouds and radiation that are currently in use on research aircraft around the world. Description of the technology is at a level sufficient for introducing the basic principles of operation and an extensive list of references for further reading is given. A number of newer instruments that implement emerging technology are described and the review concludes with a description of some of the most important measurement challenges that remain. This overview is a synthesis of material from a reference book that is currently in preparation and that will be published in 2012 by Wiley.

  16. PHIPS-HALO: the airborne Particle Habit Imaging and Polar Scattering probe - Part 1: Design and operation

    NASA Astrophysics Data System (ADS)

    Abdelmonem, Ahmed; Järvinen, Emma; Duft, Denis; Hirst, Edwin; Vogt, Steffen; Leisner, Thomas; Schnaiter, Martin

    2016-07-01

    The number and shape of ice crystals present in mixed-phase and ice clouds influence the radiation properties, precipitation occurrence and lifetime of these clouds. Since clouds play a major role in the climate system, influencing the energy budget by scattering sunlight and absorbing heat radiation from the earth, it is necessary to investigate the optical and microphysical properties of cloud particles particularly in situ. The relationship between the microphysics and the single scattering properties of cloud particles is usually obtained by modelling the optical scattering properties from in situ measurements of ice crystal size distributions. The measured size distribution and the assumed particle shape might be erroneous in case of non-spherical ice particles. There is a demand to obtain both information correspondently and simultaneously for individual cloud particles in their natural environment. For evaluating the average scattering phase function as a function of ice particle habit and crystal complexity, in situ measurements are required. To this end we have developed a novel airborne optical sensor (PHIPS-HALO) to measure the optical properties and the corresponding microphysical parameters of individual cloud particles simultaneously. PHIPS-HALO has been tested in the AIDA cloud simulation chamber and deployed in mountain stations as well as research aircraft (HALO and Polar 6). It is a successive version of the laboratory prototype instrument PHIPS-AIDA. In this paper we present the detailed design of PHIPS-HALO, including the detection mechanism, optical design, mechanical construction and aerodynamic characterization.

  17. Flow Mapping in a Gas-Solid Riser via Computer Automated Radioactive Particle Tracking (CARPT)

    SciTech Connect

    Muthanna Al-Dahhan; Milorad P. Dudukovic; Satish Bhusarapu; Timothy J. O'hern; Steven Trujillo; Michael R. Prairie

    2005-06-04

    Statement of the Problem: Developing and disseminating a general and experimentally validated model for turbulent multiphase fluid dynamics suitable for engineering design purposes in industrial scale applications of riser reactors and pneumatic conveying, require collecting reliable data on solids trajectories, velocities ? averaged and instantaneous, solids holdup distribution and solids fluxes in the riser as a function of operating conditions. Such data are currently not available on the same system. Multiphase Fluid Dynamics Research Consortium (MFDRC) was established to address these issues on a chosen example of circulating fluidized bed (CFB) reactor, which is widely used in petroleum and chemical industry including coal combustion. This project addresses the problem of lacking reliable data to advance CFB technology. Project Objectives: The objective of this project is to advance the understanding of the solids flow pattern and mixing in a well-developed flow region of a gas-solid riser, operated at different gas flow rates and solids loading using the state-of-the-art non-intrusive measurements. This work creates an insight and reliable database for local solids fluid-dynamic quantities in a pilot-plant scale CFB, which can then be used to validate/develop phenomenological models for the riser. This study also attempts to provide benchmark data for validation of Computational Fluid Dynamic (CFD) codes and their current closures. Technical Approach: Non-Invasive Computer Automated Radioactive Particle Tracking (CARPT) technique provides complete Eulerian solids flow field (time average velocity map and various turbulence parameters such as the Reynolds stresses, turbulent kinetic energy, and eddy diffusivities). It also gives directly the Lagrangian information of solids flow and yields the true solids residence time distribution (RTD). Another radiation based technique, Computed Tomography (CT) yields detailed time averaged local holdup profiles at

  18. Surface charge accumulation of particles containing radionuclides in open air.

    PubMed

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. However, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. A charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. The study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  19. Surface charge accumulation of particles containing radionuclides in open air

    SciTech Connect

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify the particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.

  20. Surface charge accumulation of particles containing radionuclides in open air

    DOE PAGES

    Kim, Yong-ha; Yiacoumi, Sotira; Tsouris, Costas

    2015-05-01

    Radioactivity can induce charge accumulation on radioactive particles. But, electrostatic interactions caused by radioactivity are typically neglected in transport modeling of radioactive plumes because it is assumed that ionizing radiation leads to charge neutralization. The assumption that electrostatic interactions caused by radioactivity are negligible is evaluated here by examining charge accumulation and neutralization on particles containing radionuclides in open air. Moreover, a charge-balance model is employed to predict charge accumulation on radioactive particles. It is shown that particles containing short-lived radionuclides can be charged with multiple elementary charges through radioactive decay. The presence of radioactive particles can significantly modify themore » particle charge distribution in open air and yield an asymmetric bimodal charge distribution, suggesting that strong electrostatic particle interactions may occur during short- and long-range transport of radioactive particles. Possible effects of transported radioactive particles on electrical properties of the local atmosphere are reported. Our study offers insight into transport characteristics of airborne radionuclides. Results are useful in atmospheric transport modeling of radioactive plumes.« less

  1. Investigation of fluorine content in PM2.5 airborne particles of Istanbul, Turkey.

    PubMed

    Ozbek, Nil; Baltaci, Hakki; Baysal, Asli

    2016-07-01

    Fluorine determination in airborne samples is important due to its spread into the air from both natural and artificial sources. It can travel by wind over large distances before depositing on the Earth's surface. Its concentration in various matrices are limited and controlled by the regulations for causing health risks associated with environmental exposures. In this work, fluorine was determined in PM2.5 airborne samples by high-resolution continuum source electrothermal atomic absorption spectrometry. For these purpose, the PM2.5 airborne particulates were collected on quartz filters using high-volume samplers (500 L/min) in Istanbul (Turkey) for 96 h during January to June in 2 years. Then, instrumental and experimental parameters were optimized for the analyte in airborne samples. The validity of the method for the analyte was tested using standard reference material, and certified values were found in the limits of 95 % confidence level. The fluorine concentrations and meteorological conditions were compared statistically.

  2. Fluorescence Spectra of Individual Flowing Airborne Biological Particles Measured in Real Time

    DTIC Science & Technology

    2001-02-01

    nucleotides, secondary metabolites , and components of culture media (these may have more variability from sample to sample than do the amino acids...Grinshpun, K. Willeke, and E. C. Cole, Characteristics of airborne actinomycete spores. Appl. Environ. Microbiol. 64 (1998), pp 3807–3812. 20. Franc, G. D

  3. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry.

    PubMed

    Kero, Ida Teresia; Jørgensen, Rikke Bramming

    2016-09-01

    The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPI(TM)), a Fast Mobility Particle Sizer (FMPS(TM)), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification.

  4. Comparison of Three Real-Time Measurement Methods for Airborne Ultrafine Particles in the Silicon Alloy Industry

    PubMed Central

    Kero, Ida Teresia; Jørgensen, Rikke Bramming

    2016-01-01

    The aim of this study was to compare the applicability and the correlation between three commercially available instruments capable of detection, quantification, and characterization of ultrafine airborne particulate matter in the industrial setting of a tapping area in a silicon alloy production plant. The number concentration of ultrafine particles was evaluated using an Electric Low Pressure Impactor (ELPITM), a Fast Mobility Particle Sizer (FMPSTM), and a Condensation Particle Counter (CPC). The results are discussed in terms of particle size distribution and temporal variations linked to process operations. The instruments show excellent temporal covariation and the correlation between the FMPS and ELPI is good. The advantage of the FMPS is the excellent time- and size resolution of the results. The main advantage of the ELPI is the possibility to collect size-fractionated samples of the dust for subsequent analysis by, for example, electron microscopy. The CPC does not provide information about the particle size distribution and its correlation to the other two instruments is somewhat poor. Nonetheless, the CPC gives basic, real-time information about the ultrafine particle concentration and can therefore be used for source identification. PMID:27598180

  5. Airborne measurements of cloud-forming nuclei and aerosol particles in stabilized ground clouds produced by solid rocket booster firings

    NASA Technical Reports Server (NTRS)

    Hindman, E. E., II; Ala, G. G.; Parungo, F. P.; Willis, P. T.; Bendura, R. J.; Woods, D.

    1978-01-01

    Airborne measurements of cloud volumes, ice nuclei and cloud condensation nuclei, liquid particles, and aerosol particles were obtained from stabilized ground clouds (SGCs) produced by Titan 3 launches at Kennedy Space Center, 20 August and 5 September 1977. The SGCs were bright, white, cumulus clouds early in their life and contained up to 3.5 g/m3 of liquid in micron to millimeter size droplets. The measured cloud volumes were 40 to 60 cu km five hours after launch. The SGCs contained high concentrations of cloud condensation nuclei active at 0.2%, 0.5%, and 1.0% supersaturation for periods of three to five hours. The SGCs also contained high concentrations of submicron particles. Three modes existed in the particle population: a 0.05 to 0.1 micron mode composed of aluminum-containing particles, a 0.2 to 0.8 micron mode, and a 2.0 to 10 micron mode composed of particles that contained primarily aluminum.

  6. RADIO-ACTIVE TRANSDUCER

    DOEpatents

    Wanetick, S.

    1962-03-01

    ABS>ure the change in velocity of a moving object. The transducer includes a radioactive source having a collimated beam of radioactive particles, a shield which can block the passage of the radioactive beam, and a scintillation detector to measure the number of radioactive particles in the beam which are not blocked by the shield. The shield is operatively placed across the radioactive beam so that any motion normal to the beam will cause the shield to move in the opposite direction thereby allowing more radioactive particles to reach the detector. The number of particles detected indicates the acceleration. (AEC)

  7. Measurements of condensation nuclei in the Airborne Arctic Stratospheric Expedition - Observations of particle production in the polar vortex

    NASA Technical Reports Server (NTRS)

    Wilson, J. C.; Stolzenburg, M. R.; Clark, W. E.; Loewenstein, M.; Ferry, G. V.; Chan, K. R.

    1990-01-01

    The ER-2 Condensation Nucleus Counter (ER-2 CNC) was operated in the Airborne Arctic Stratospheric Expedition (AASE) in January and February 1989. The ER-2 CNC measures the mixing ratio of particles, CN, with diameters from approximately 0.02 to approximately 1 micron. The spatial distribution of CN in the Arctic polar vortex was found to resemble that measured in the Antarctic in the Spring of 1987. The vertical profile of CN in the vortex was lowered by subsidence. At altitudes above the minimum in the CN mixing ratio profile, CN mixing ratios correlated negatively with that of N2O, demonstrating new particle production. CN serve as nuclei in the formation of Polar Stratospheric Clouds (PSCs) and the concentration of CN can affect PSC properties.

  8. The inflammatory response in lungs of rats exposed on the airborne particles collected during different seasons in four European cities.

    PubMed

    Halatek, Tadeusz; Stepnik, Maciej; Stetkiewicz, Jan; Krajnow, Aleksander; Kur, Barbara; Szymczak, Wieslaw; Rydzynski, Konrad; Dybing, Erik; Cassee, Fleming R

    2011-01-01

    Epidemiological studies have reported associations of ambient particulate air pollution, especially particulate matter (PM) less than 10 μm with exacerbations of asthma and chronic obstructive pulmonary disease. In an in vivo model, we have tested the toxicity of urban airborne particles collected during spring, summer, and winter seasons in four cities (Amsterdam, Lodz, Oslo, and Rome) spread across Europe. The seasonal differences in inflammatory responses were striking, and almost all the study parameters were affected by PM. Coarse fractions of the urban particle samples were less potent per unit mass than the fine fractions in increasing cytokine [macrophage inflammatory protein (MIP)-2 and tumor necrosis factor (TNF)-α] levels and in reducing Clara-cell secretory protein (CC16) levels. This study shows that PM collected at 4 contrasting sites across Europe and during different seasons have differences in toxic potency. These differences were even more prominent between the fine and coarse fractions of the PM.

  9. Airborne Biogenic Particles in the Snow of the Cities of the Russian Far East as Potential Allergic Compounds

    PubMed Central

    Golokhvast, Kirill S.

    2014-01-01

    This paper presents an analysis of airborne biogenic particles (1 mkm–1 mm) found in the snow in several cities of the Russian Far East during 2010–2013. The most common was vegetational terraneous detritus (fragments of tree and grass leaves) followed by animal hair, small insects and their fragments, microorganisms of aeroplankton, and equivocal biological garbage. Specific components were found in samples from locations close to bodies of water such as fragments of algae and mollusc shells and, marine invertebrates (needles of sea urchins and shell debris of arthropods). In most locations across the Far East (Vladivostok, Khabarovsk, Blagoveshchensk, and Ussuriysk), the content of biogenic particles collected in the winter did not exceed 10% of the total particulate matter, with the exception of Birobidzhan and the nature reserve Bastak, where it made up to 20%. Most of all biogenic compounds should be allergic: hair, fragments of tree and grass leaves, insects, and microorganisms. PMID:25140327

  10. Size distribution of airborne particle-bound polybrominated diphenyl ethers and its implications for dry and wet deposition.

    PubMed

    Luo, Pei; Ni, Hong-Gang; Bao, Lian-Jun; Li, Shao-Meng; Zeng, Eddy Y

    2014-12-02

    Size distribution of particles in part dictates the environmental behavior of particle-bound organic pollutants in the atmosphere. The present study was conducted to examine the potential mechanisms responsible for the distribution of organic pollutants in size fractionated particles and their environmental implications, using an e-waste recycling zone in South China as a case study. Size-fractionated atmospheric particles were collected at the heights of 1.5, 5, and 20 m near two residential apartments and analyzed for polybrominated diphenyl ethers (PBDEs). The concentrations of particle-bound ΣPBDE (sum of 18 PBDE congeners) were significantly greater at 5 and 20 m than those at 1.5 m. The size-fractionated distributions of airborne ΣPBDE displayed trimodal peaks in 0.10–0.18, 1.8–3.2, and 10–18 μm at 1.5 m but only an unimodal peak in 1.0–1.8 μm at 20 m height. Emission sources, resuspension of dust and soil, and volatility of PBDEs were important factors influencing the size distribution of particle-bound PBDEs. The dry deposition fluxes of particle-bound PBDE estimated from the measured data in the present study were approximately twice the estimated wet deposition fluxes, with a total deposition flux of 3000 ng m(–2) d(–1). The relative contributions of particles to dry and wet deposition fluxes were also size-dependent, e.g., coarse (aerodynamic diameters (Dp) > 1.8 μm) and fine (Dp < 1.8 μm) particles dominated the dry and wet deposition fluxes of PBDEs, respectively.

  11. Characterization and Source Term Assessments of Radioactive Particles from Marshall Islands Using Non-Destructive Analytical Techniques

    SciTech Connect

    Jernstrom, J; Eriksson, M; Simon, R; Tamborini, G; Bildstein, O; Carlos-Marquez, R; Kehl, S R; Betti, M; Hamilton, T

    2005-06-11

    A considerable fraction of radioactivity entering the environment from different nuclear events is associated with particles. The impact of these events can only be fully assessed where there is some knowledge about the mobility of particle bound radionuclides entering the environment. The behavior of particulate radionuclides is dependent on several factors, including the physical, chemical and redox state of the environment, the characteristics of the particles (e.g., the chemical composition, crystallinity and particle size) and on the oxidative state of radionuclides contained in the particles. Six plutonium-containing particles stemming from Runit Island soil (Marshall Islands) were characterized using non-destructive analytical and microanalytical methods. By determining the activity of {sup 239,240}Pu and {sup 241}Am isotopes from their gamma peaks structural information related to Pu matrix was obtained, and the source term was revealed. Composition and elemental distribution in the particles were studied with synchrotron radiation based micro X-ray fluorescence (SR-{mu}-XRF) spectrometry. Scanning electron microscope equipped with energy dispersive X-ray detector (SEMEDX) and secondary ion mass spectrometer (SIMS) were used to examine particle surfaces. Based on the elemental composition the particles were divided into two groups; particles with plain Pu matrix, and particles where the plutonium is included in Si/O-rich matrix being more heterogeneously distributed. All of the particles were identified as fragments of initial weapons material. As containing plutonium with low {sup 240}Pu/{sup 239}Pu atomic ratio, {approx}2-6%, which corresponds to weapons grade plutonium, the source term was identified to be among the safety tests conducted in the history of Runit Island.

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

    NASA Astrophysics Data System (ADS)

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

    2015-04-01

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

  13. Characterizing the effective density and primary particle diameter of airborne nanoparticles produced by spark discharge using mobility and mass measurements (tandem DMA/APM)

    NASA Astrophysics Data System (ADS)

    Charvet, Augustin; Bau, Sébastien; Paez Coy, Natalia Estefania; Bémer, Denis; Thomas, Dominique

    2014-05-01

    Nanoparticles are increasingly used in a wide variety of industries. As yet, their health effects are incompletely characterized. Effective density is among the key characteristics of airborne nanoparticles due to its role in particle deposition in the human respiratory tract and in the conversion of number distributions to mass distributions. Because it cannot be measured directly, different methods have been developed to accede to this parameter. The approach chosen in this study is based on the tandem measurement of airborne nanoparticles electrical mobility and mass (tandem differential mobility analyzer/aerosol particle mass analyzer), which major advantage lies in the absence of hypothesis contrary to the tandem differential mobility analyzer/electrical low pressure impactor (DMA/ELPI). The methodology was first applied to spherical model particles to validate the associated data treatment and protocol. In particular, the influence of APM rotational velocity and airflow rate were investigated with regards to the separation of multiply charged particles and electrometer signal. It emerged from experimental data that a compromise between separation efficiency and detection limit shall be found, depending on the nanoparticles to characterize. Accounting for their wide use in different domains, airborne nanoparticles of constantan®, copper, graphite, iron, silver and titanium, produced by spark discharge appear to be representative of ultrafine particles stemming from different industrial processes. In addition to their effective density, the mass-mobility exponents and primary particle diameters were determined for these particles, and found to agree well with published data.

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

    NASA Astrophysics Data System (ADS)

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

    2015-09-01

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

  15. [The Patterns of Behavior of Radioactive Particles in the Food Chain of Cattle and Transport in the Gastrointestinal Tract of Animals].

    PubMed

    Kozmin, G V; Yepimakhov, V G

    2015-01-01

    The analysis of the patterns of behavior of polydisperse radioactive silicate particles in the components of the food chain of cattle is presented. It is shown that the composition of the size distribution of radioactive particles taken into animal organisms differs from the original composition of the particles deposited on the surface of pasture vegetation, and from dispersion of the particles in the aboveground biomass of vegetation at the time of grazing. The intake of particles into animal organisms is reduced with the increase of their size, and for the particle fraction of 400-800 microns it is about 10 times less than for the fine fraction (< 100 microns). The mathematical compartment model ofthe transport of polydisperse radioactive particles in the digestive tract of cattle has been developed. It is found that the elimination rate of radioactive particles from the animal organism depends on their sizes. Deposition of particles on the fundic surface of the wall ventral sac of rumen and reticulum as well as their long stay in comparison with the chyme in abomasum was noted. The maximum levels of irradiation are formed in these parts of the digestive tract of cattle.

  16. Acoustophoretic separation of airborne millimeter-size particles by a Fresnel lens

    PubMed Central

    Cicek, Ahmet; Korozlu, Nurettin; Adem Kaya, Olgun; Ulug, Bulent

    2017-01-01

    We numerically demonstrate acoustophoretic separation of spherical solid particles in air by means of an acoustic Fresnel lens. Beside gravitational and drag forces, freely-falling millimeter-size particles experience large acoustic radiation forces around the focus of the lens, where interplay of forces lead to differentiation of particle trajectories with respect to either size or material properties. Due to the strong acoustic field at the focus, radiation force can divert particles with source intensities significantly smaller than those required for acoustic levitation in a standing field. When the lens is designed to have a focal length of 100 mm at 25 kHz, finite-element method simulations reveal a sharp focus with a full-width at half-maximum of 0.5 wavelenghts and a field enhancement of 18 dB. Through numerical calculation of forces and simulation of particle trajectories, we demonstrate size-based separation of acrylic particles at a source sound pressure level of 153 dB such that particles with diameters larger than 0.5 mm are admitted into the central hole, whereas smaller particles are rejected. Besides, efficient separation of particles with similar acoustic properties such as polyethylene, polystyrene and acrylic particles of the same size is also demonstrated. PMID:28252033

  17. Acoustophoretic separation of airborne millimeter-size particles by a Fresnel lens

    NASA Astrophysics Data System (ADS)

    Cicek, Ahmet; Korozlu, Nurettin; Adem Kaya, Olgun; Ulug, Bulent

    2017-03-01

    We numerically demonstrate acoustophoretic separation of spherical solid particles in air by means of an acoustic Fresnel lens. Beside gravitational and drag forces, freely-falling millimeter-size particles experience large acoustic radiation forces around the focus of the lens, where interplay of forces lead to differentiation of particle trajectories with respect to either size or material properties. Due to the strong acoustic field at the focus, radiation force can divert particles with source intensities significantly smaller than those required for acoustic levitation in a standing field. When the lens is designed to have a focal length of 100 mm at 25 kHz, finite-element method simulations reveal a sharp focus with a full-width at half-maximum of 0.5 wavelenghts and a field enhancement of 18 dB. Through numerical calculation of forces and simulation of particle trajectories, we demonstrate size-based separation of acrylic particles at a source sound pressure level of 153 dB such that particles with diameters larger than 0.5 mm are admitted into the central hole, whereas smaller particles are rejected. Besides, efficient separation of particles with similar acoustic properties such as polyethylene, polystyrene and acrylic particles of the same size is also demonstrated.

  18. Design and Laboratory Evaluation of a Sequential Spot Sampler for Time-Resolved Measurement of Airborne Particle Composition

    PubMed Central

    Eiguren Fernandez, Arantzazu; Lewis, Gregory S.; Hering, Susanne V.

    2014-01-01

    A new sampling approach has been developed to enable affordable, time-resolved monitoring of particulate chemical compositions, and more generally to provide concentrated samples of airborne particles. Using a newly developed, moderated water-based condensational growth technology, individual particle samples are deposited in a 1-mm diameter dry “spot”. The moderated condensation technology enables this collection with minimal temperature rise, providing robust collection for volatile constituents. Measured collection efficiencies are above 95% for particles in the size range from 0.010 μm to 2.5 μm. A set of 20 or more time-resolved samples, plus blanks, may be collected onto a multiwell collection plate. For chemical analysis the plate is returned to the laboratory, and placed directly into a modified autosampler, without extraction or preparation. The autosampler handles the addition of eluent, extraction, and sample injection without user manipulation. This paper presents the design and laboratory evaluation of a 1.5 L/min sampling rate version of this system. PMID:25045199

  19. Airborne Particles: What We Have Learned About Their Role in Climate from Remote Sensing, and Prospects for Future Advances

    NASA Technical Reports Server (NTRS)

    Kahn, Ralph A.

    2013-01-01

    Desert dust, wildfire smoke, volcanic ash, biogenic and urban pollution particles, all affect the regional-scale climate of Earth in places and at times; some have global-scale impacts on the column radiation balance, cloud properties, atmospheric stability structure, and circulation patterns. Remote sensing has played a central role in identifying the sources and transports of airborne particles, mapping their three-dimensional distribution and variability, quantifying their amount, and constraining aerosol air mass type. The measurements obtained from remote sensing have strengths and limitations, and their value for characterizing Earths environment is enhanced immensely when they are combined with direct, in situ observations, and used to constrain aerosol transport and climate models. A similar approach has been taken to study the role particles play in determining the climate of Mars, though based on far fewer observations. This presentation will focus what we have learned from remote sensing about the impacts aerosol have on Earths climate; a few points about how aerosols affect the climate of Mars will also be introduced, in the context of how we might assess aerosol-climate impacts more generally on other worlds.

  20. Highly Integrated Polysulfone/polyacrylonitrile/polyamide-6 Air Filter for Multi-level Physical Sieving Airborne Particles.

    PubMed

    Zhang, Shichao; Tang, Ning; Cao, Leitao; Yin, Xia; Yu, Jianyong; Ding, Bin

    2016-10-04

    Rational structural design involving controlled pore size, high porosity, and particle-targeted function is critical to the realization of highly efficient air filters, and the filter with absolute particle-screen ability has significant technological implications for applications including individual protection, industrial security, and environmental governance; however, it remains an ongoing challenge. In this study, we first report a facile and scalable strategy to fabricate the highly integrated polysulfone/polyacrylonitrile/polyamide-6 (PSU/PAN/PA-6) air filter for multi-level physical sieving airborne particles via sequential electrospinning. Our strategy causes the PSU microfiber (diameter of ~1 μm) layer, PAN nanofiber (diameter of ~200 nm) layer, and PA-6 nanonets (diameter of ~20 nm) layer to orderly assemble into the integrated filter with gradually varied pore structures and high porosity; thus enables the filter to work efficiently by employing different layers to cut off penetration of particles with certain size that exceeds the designed threshold level. By virtue of its elaborate gradient structure, robust hydrophobicity (WCA of ~130o), and superior mechanical property (5.6 MPa), our PSU/PAN/PA-6 filter even can filtrate the 300 nm particles with a high removal efficiency of 99.992% and a low pressure drop of 118 Pa in the way of physical sieving manner, which completely gets rid of the negative impact from high airflow speed, electret failure, and high humidity. It is expected that our highly integrated filter has wider applications for filtration and separation, and design of 3D functional structure in the future.

  1. Use of a size-resolved 1-D resuspension scheme to evaluate resuspended radioactive material associated with mineral dust particles from the ground surface.

    PubMed

    Ishizuka, Masahide; Mikami, Masao; Tanaka, Taichu Y; Igarashi, Yasuhito; Kita, Kazuyuki; Yamada, Yutaka; Yoshida, Naohiro; Toyoda, Sakae; Satou, Yukihiko; Kinase, Takeshi; Ninomiya, Kazuhiko; Shinohara, Atsushi

    2017-01-01

    A size-resolved, one-dimensional resuspension scheme for soil particles from the ground surface is proposed to evaluate the concentration of radioactivity in the atmosphere due to the secondary emission of radioactive material. The particle size distributions of radioactive particles at a sampling point were measured and compared with the results evaluated by the scheme using four different soil textures: sand, loamy sand, sandy loam, and silty loam. For sandy loam and silty loam, the results were in good agreement with the size-resolved atmospheric radioactivity concentrations observed at a school ground in Tsushima District, Namie Town, Fukushima, which was heavily contaminated after the Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. Though various assumptions were incorporated into both the scheme and evaluation conditions, this study shows that the proposed scheme can be applied to evaluate secondary emissions caused by aeolian resuspension of radioactive materials associated with mineral dust particles from the ground surface. The results underscore the importance of taking soil texture into account when evaluating the concentrations of resuspended, size-resolved atmospheric radioactivity.

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

    PubMed

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-10-01

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

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

    PubMed Central

    Heredia Rivera, Birmania; Gerardo Rodriguez, Martín

    2016-01-01

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

  4. A benchmark for numerical scheme validation of airborne particle exposure in street canyons.

    PubMed

    Marini, S; Buonanno, G; Stabile, L; Avino, P

    2015-02-01

    Measurements of particle concentrations and distributions in terms of number, surface area, and mass were performed simultaneously at eight sampling points within a symmetric street canyon of an Italian city. The aim was to obtain a useful benchmark for validation of wind tunnel experiments and numerical schemes: to this purpose, the influence of wind directions and speeds was considered. Particle number concentrations (PNCs) were higher on the leeward side than the windward side of the street canyon due to the wind vortex effect. Different vertical PNC profiles were observed between the two canyon sides depending on the wind direction and speed at roof level. A decrease in particle concentrations was observed with increasing rooftop wind speed, except for the coarse fraction indicating a possible particle resuspension due to the traffic and wind motion. This study confirms that particle concentration fields in urban street canyons are strongly influenced by traffic emissions and meteorological parameters, especially wind direction and speed.

  5. LOAC (Light Optical Particle Counter): a new small aerosol counter with particle characterization capabilities for surface and airborne measurements

    NASA Astrophysics Data System (ADS)

    Renard, Jean-Baptiste; Berthet, Gwenael; Jégou, Fabrice; Jeannot, Matthieu; Jourdain, Line; Dulac, François; Mallet, Marc; Dupont, Jean-Charles; Thaury, Claire; Tonnelier, Thierry; Verdier, Nicolas; Charpentier, Patrick

    2013-04-01

    The determination of the size distribution of tropospheric and stratospheric aerosols with conventional optical counters is difficult when different natures of particles are present (droplets, soot, mineral dust, secondary organic or mineral particles...). Also, a light and cheap aerosol counter that can be used at ground, onboard drones or launched under all kinds of atmospheric balloons can be very useful during specific events as volcanic plumes, desert dust transport or local pollution episodes. These goals can be achieved thanks to a new generation of aerosol counter, called LOAC (Light Optical Aerosol Counter). The instrument was developed in the frame of a cooperation between French scientific laboratories (CNRS), the Environnement-SA and MeteoModem companies and the French Space Agency (CNES). LOAC is a small optical particle counter/sizer of ~250 grams, having a low electrical power consumption. The measurements are conducted at two scattering angles. The first one, at 12°, is used to determine the aerosol particle concentrations in 19 size classes within a diameter range of 0.3-100 micrometerers. At such an angle close to forward scattering, the signal is much more intense and the measurements are the least sensitive to the particle nature. The second angle is at 60°, where the scattered light is strongly dependent on the particle refractive index and thus on the nature of the aerosols. The ratio of the measurements at the two angles is used to discriminate between the different types of particles dominating the nature of the aerosol particles in the different size classes. The sensor particularly discriminates wet or liquid particles, soil dust and soot. Since 2011, we have operated LOAC in various environments (Arctic, Mediterranean, urban and peri-urban…) under different kinds of balloons including zero pressure stratospheric, tethered, drifting tropospheric, and meteorological sounding balloons. For the last case, the total weight of the gondola

  6. Using Atmospheric Dispersion Theory to Inform the Design of a Short-lived Radioactive Particle Release Experiment

    SciTech Connect

    Rishel, Jeremy P.; Keillor, Martin E.; Arrigo, Leah M.; Baciak, James E.; Detwiler, Rebecca S.; Kernan, Warnick J.; Kirkham, Randy R.; Milbrath, Brian D.; Seifert, Allen; Seifert, Carolyn E.; Smart, John E.

    2016-01-01

    Atmospheric dispersion theory can be used to predict ground deposition of particulates downwind of a radionuclide release. This paper utilizes standard formulations found in Gaussian plume models to inform the design of an experimental release of short-lived radioactive particles into the atmosphere. Specifically, a source depletion algorithm is used to determine the optimum particle size and release height that maximizes the near-field deposition while minimizing the both the required source activity and the fraction of activity lost to long-distance transport. The purpose of the release is to provide a realistic deposition pattern that might be observed downwind of a small-scale vent from an underground nuclear explosion. The deposition field will be used, in part, to investigate several techniques of gamma radiation survey and spectrometry that could be utilized by an On-Site Inspection team under the verification regime of the Comprehensive Nuclear-Test-Ban Treaty.

  7. Vacuum cleaner emissions as a source of indoor exposure to airborne particles and bacteria.

    PubMed

    Knibbs, Luke D; He, Congrong; Duchaine, Caroline; Morawska, Lidia

    2012-01-03

    Vacuuming can be a source of indoor exposure to biological and nonbiological aerosols, although there are few data that describe the magnitude of emissions from the vacuum cleaner itself. We therefore sought to quantify emission rates of particles and bacteria from a large group of vacuum cleaners and investigate their potential determinants, including temperature, dust bags, exhaust filters, price, and age. Emissions of particles between 0.009 and 20 μm and bacteria were measured from 21 vacuums. Ultrafine (<100 nm) particle emission rates ranged from 4.0 × 10(6) to 1.1 × 10(11) particles min(-1). Emission of 0.54-20 μm particles ranged from 4.0 × 10(4) to 1.2 × 10(9) particles min(-1). PM(2.5) emissions were between 2.4 × 10(-1) and 5.4 × 10(3) μg min(-1). Bacteria emissions ranged from 0 to 7.4 × 10(5) bacteria min(-1) and were poorly correlated with dust bag bacteria content and particle emissions. Large variability in emission of all parameters was observed across the 21 vacuums, which was largely not attributable to the range of determinant factors we assessed. Vacuum cleaner emissions contribute to indoor exposure to nonbiological and biological aerosols when vacuuming, and this may vary markedly depending on the vacuum used.

  8. High-rate axial-field ionization chamber for particle identification of Radioactive beams

    NASA Astrophysics Data System (ADS)

    Desouza, Romualdo; Vadas, Justin; Singh, Varinderjit; Visser, G.; Alexander, A.; Hudan, S.; Huston, J.; Wiggins, B.; Chbihi, A.; Famiano, M.; Bischak, M.

    2017-01-01

    The design, construction and performance characteristics of a simple axial-field ionization chamber suitable for identifying ions in a radioactive beam are presented. The detector is optimized for use with low-energy radioactive beams (<) 5 MeV/A. A fast charge sensitive amplifier (CSA) integrated into the detector design is also described. Coupling this fast CSA to the axial field ionization chamber produces an output pulse with a rise-time of 60 to 70 ns and a fall time of 100 ns, making the detector capable of sustaining a relatively high rate while providing a time resolution of 6 to 8 ns. Tests with an α source establish the detector energy resolution as 8 % for an energy deposit of 3.5 MeV. Beam tests indicate that the detector is an effective tool for the characterization of low-energy radioactive beams at beam intensities up to 3 x 105 ions/s. Supported by the U.S. DOE under Award # DE-FG02-88ER-40404 and the NSF under Grant No. 1342962.

  9. High-rate axial-field ionization chamber for particle identification of radioactive beams

    NASA Astrophysics Data System (ADS)

    Vadas, J.; Singh, Varinderjit; Visser, G.; Alexander, A.; Hudan, S.; Huston, J.; Wiggins, B. B.; Chbihi, A.; Famiano, M.; Bischak, M. M.; deSouza, R. T.

    2016-11-01

    The design, construction and performance characteristics of a simple axial-field ionization chamber suitable for identifying ions in a radioactive beam are presented. Optimized for use with low-energy radioactive beams (< 5 MeV / A) the detector presents only three 0.5 μm/cm2 foils to the beam in addition to the detector gas. A fast charge sensitive amplifier (CSA) integrated into the detector design is also described. Coupling this fast CSA to the axial field ionization chamber produces an output pulse with a risetime of 60-70 ns and a fall time of 100 ns, making the detector capable of sustaining a relatively high rate and providing a time resolution of 6-8 ns. Tests with an α source establish the detector energy resolution as ∼ 8 % for an energy deposit of ∼3.5 MeV. The energy resolution with beams of 2.5 and 4.0 MeV/A 39K ions and the dependence of the energy resolution on beam intensity is measured. At an instantaneous rate of 3×105 ions/s the energy resolution has degraded to 14% with a pileup of 12%. The good energy resolution of this detector at rates up to 3×105 ions/s makes it an effective tool in the characterization of low-energy radioactive beams.

  10. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions

    PubMed Central

    Perraud, Véronique; Horne, Jeremy R.; Martinez, Andrew S.; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L.; Wingen, Lisa M.; Dabdub, Donald; Blake, Donald R.; Gerber, R. Benny; Finlayson-Pitts, Barbara J.

    2015-01-01

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine–California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs. PMID:26483454

  11. The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions.

    PubMed

    Perraud, Véronique; Horne, Jeremy R; Martinez, Andrew S; Kalinowski, Jaroslaw; Meinardi, Simone; Dawson, Matthew L; Wingen, Lisa M; Dabdub, Donald; Blake, Donald R; Gerber, R Benny; Finlayson-Pitts, Barbara J

    2015-11-03

    Sulfuric acid (H2SO4), formed from oxidation of sulfur dioxide (SO2) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO2 during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H2SO4 and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO2 decline. The 3-dimensional University of California Irvine-California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H2SO4, and SO2 under current emissions of fossil fuel-associated SO2 and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO2 emissions case, particle formation potential from H2SO4 will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H2SO4 of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.

  12. Assessment of exposure to airborne ultrafine particles in the urban environment of Lisbon, Portugal.

    PubMed

    Albuquerque, P C; Gomes, J F; Bordado, J C

    2012-04-01

    The aim of this study was the assessment of exposure to ultrafine in the urban environment ofLisbon, Portugal, due to automobile traffic, and consisted of the determination of deposited alveolar surface area in an avenue leading to the town center during late spring. This study revealed differentiated patterns for weekdays and weekends, which could be related with the fluxes of automobile traffic. During a typical week, ultrafine particles alveolar deposited surface area varied between 35.0 and 89.2 microm2/cm3, which is comparable with levels reported for other towns such in Germany and the United States. These measurements were also complemented by measuring the electrical mobility diameter (varying from 18.3 to 128.3 nm) and number of particles that showed higher values than those previously reported for Madrid and Brisbane. Also, electron microscopy showed that the collected particles were composed of carbonaceous agglomerates, typical of particles emitted by the exhaustion of diesel vehicles.

  13. Fluorescence-Based Classification with Selective Collection and Identification of Individual Airborne Bioaerosol Particles

    NASA Astrophysics Data System (ADS)

    Huang, Hermes C.; Pan, Yong-Le; Hill, Steven C.; Pinnick, Ronald G.

    The development of techniques for bioaerosol detection and characterization has flourished during the last decade. A brief summary of the advancements of Prof. Richard K. Chang and his research group at Yale University, together with collaborators at the US Army Research Laboratory (ARL), is given here. We focus on the development of the Single-Particle Fluorescence Spectrometer (SPFS). The SPFS is capable of real-time, in-situ monitoring, classification, sorting, and collection of bioaerosols. The SPFS rapidly samples single aerosol particles having sizes in the 1- to 10-μmdiameter range, illuminates them one-by-one with a pulsed UV laser, disperses the fluorescence generated, measures the fluorescence spectra and elastic scattering, and uses these measurements to classify the particles. Bioaerosol particles can be sorted one-by-one, according to their fluorescence spectra, using an aerodynamic puffer, and collected to yield an enriched aerosol sample defined by the particles' fluorescence "signature." A system to further identify specific particle types in the enriched sample has also been investigated. The intent is to provide a system capable of monitoring harmful aerosols in the highly variable and complex atmospheric environment. Here we describe our investigations of ultraviolet-laser-induced fluorescence (UV-LIF) of aerosols, the evolution of the SPFS technology, and the application of the SPFS to characterization of atmospheric aerosols at Adelphi, MD, New Haven, CT, and Las Cruces, NM, USA.

  14. Characterization of exposures among cemented tungsten carbide workers. Part I: Size-fractionated exposures to airborne cobalt and tungsten particles.

    PubMed

    Stefaniak, Aleksandr B; Virji, M Abbas; Day, Gregory A

    2009-07-01

    As many as 30,000 workers in the United States of America are exposed to cemented tungsten carbides (CTC), alloys composed primarily of tungsten carbide and cobalt, which are used in cutting tools. Inhalation of cobalt-containing particles may be sufficient for the development of occupational asthma, whereas tungsten carbide particles in association with cobalt particles are associated with the development of hard metal disease (HMD) and lung cancer. Historical epidemiology and exposure studies of CTC workers often rely only on measures of total airborne cobalt mass concentration. In this study, we characterized cobalt- and tungsten-containing aerosols generated during the production of CTC with emphasis on (1) aerosol "total" mass (n=252 closed-face 37 mm cassette samples) and particle size-selective mass concentrations (n=108 eight-stage cascade impactor samples); (2) particle size distributions; and (3) comparison of exposures obtained using personal cassette and impactor samplers. Total cobalt and tungsten exposures were highest in work areas that handled powders (e.g., powder mixing) and lowest in areas that handled finished product (e.g., grinding). Inhalable, thoracic, and respirable cobalt and tungsten exposures were observed in all work areas, indicating potential for co-exposures to particles capable of getting deposited in the upper airways and alveolar region of the lung. Understanding the risk of CTC-induced adverse health effects may require two exposure regimes: one for asthma and the other for HMD and lung cancer. All sizes of cobalt-containing particles that deposit in the lung and airways have potential to cause asthma, thus a thoracic exposure metric is likely biologically appropriate. Cobalt-tungsten mixtures that deposit in the alveolar region of the lung may potentially cause HMD and lung cancer, thus a respirable exposure metric for both metals is likely biologically appropriate. By characterizing size-selective and co-exposures as well as

  15. Characteristics of airborne ultrafine and coarse particles during the Australian dust storm of 23 September 2009

    NASA Astrophysics Data System (ADS)

    Jayaratne, E. R.; Johnson, G. R.; McGarry, P.; Cheung, H. C.; Morawska, L.

    2011-08-01

    Particle number concentrations and size distributions, visibility and particulate mass concentrations and weather parameters were monitored in Brisbane, Australia, on 23 September 2009, during the passage of a dust storm that originated 1400 km away in the dry continental interior. The dust concentration peaked at about mid-day when the hourly average PM 2.5 and PM 10 values reached 814 and 6460 μg m -3, respectively, with a sharp drop in atmospheric visibility. A linear regression analysis showed a good correlation between the coefficient of light scattering by particles (Bsp) and both PM 10 and PM 2.5. The particle number in the size range 0.5-20 μm exhibited a lognormal size distribution with modal and geometrical mean diameters of 1.6 and 1.9 μm, respectively. The modal mass was around 10 μm with less than 10% of the mass carried by particles smaller than 2.5 μm. The PM 10 fraction accounted for about 68% of the total mass. By mid-day, as the dust began to increase sharply, the ultrafine particle number concentration fell from about 6 × 10 3 cm -3 to 3 × 10 3 cm -3 and then continued to decrease to less than 1 × 10 3 cm -3 by 14 h, showing a power-law decrease with Bsp with an R2 value of 0.77 ( p < 0.01). Ultrafine particle size distributions also showed a significant decrease in number during the dust storm. This is the first scientific study of particle size distributions in an Australian dust storm.

  16. Automated classification of single airborne particles from two-dimensional angle-resolved optical scattering (TAOS) patterns by non-linear filtering

    NASA Astrophysics Data System (ADS)

    Crosta, Giovanni Franco; Pan, Yong-Le; Aptowicz, Kevin B.; Casati, Caterina; Pinnick, Ronald G.; Chang, Richard K.; Videen, Gorden W.

    2013-12-01

    Measurement of two-dimensional angle-resolved optical scattering (TAOS) patterns is an attractive technique for detecting and characterizing micron-sized airborne particles. In general, the interpretation of these patterns and the retrieval of the particle refractive index, shape or size alone, are difficult problems. By reformulating the problem in statistical learning terms, a solution is proposed herewith: rather than identifying airborne particles from their scattering patterns, TAOS patterns themselves are classified through a learning machine, where feature extraction interacts with multivariate statistical analysis. Feature extraction relies on spectrum enhancement, which includes the discrete cosine FOURIER transform and non-linear operations. Multivariate statistical analysis includes computation of the principal components and supervised training, based on the maximization of a suitable figure of merit. All algorithms have been combined together to analyze TAOS patterns, organize feature vectors, design classification experiments, carry out supervised training, assign unknown patterns to classes, and fuse information from different training and recognition experiments. The algorithms have been tested on a data set with more than 3000 TAOS patterns. The parameters that control the algorithms at different stages have been allowed to vary within suitable bounds and are optimized to some extent. Classification has been targeted at discriminating aerosolized Bacillus subtilis particles, a simulant of anthrax, from atmospheric aerosol particles and interfering particles, like diesel soot. By assuming that all training and recognition patterns come from the respective reference materials only, the most satisfactory classification result corresponds to 20% false negatives from B. subtilis particles and <11% false positives from all other aerosol particles. The most effective operations have consisted of thresholding TAOS patterns in order to reject defective ones

  17. Combustion aerosols formed during burning of radioactively contaminated materials: Experimental results

    SciTech Connect

    Halverson, M.A.; Ballinger, M.Y.; Dennis, G.W.

    1987-03-01

    Safety assessments and environmental impact statements for nuclear fuel cycle facilities require an estimate of potential airborne releases. Radioactive aerosols generated by fires were investigated in experiments in which combustible solids and liquids were contaminated with radioactive materials and burned. Uranium in powder and liquid form was used to contaminate five fuel types: polychloroprene, polystyrene, polymethylmethacrylate, cellulose, and a mixture of 30% tributylphosphate (TBP) in kerosene. Heat flux, oxygen concentration, air flow, contaminant concentration, and type of ignition were varied in the experiments. The highest release (7.1 wt %) came from burning TBP/kerosene over contaminated nitric acid. Burning cellulose contaminated with uranyl nitrate hexahydrate liquid gave the lowest release (0.01 wt %). Rate of release and particle size distribution of airborne radioactive particles were highly dependent on the type of fuel burned.

  18. Experimental determination of the steady-state charging probabilities and particle size conservation in non-radioactive and radioactive bipolar aerosol chargers in the size range of 5-40 nm

    NASA Astrophysics Data System (ADS)

    Kallinger, Peter; Szymanski, Wladyslaw W.

    2015-04-01

    Three bipolar aerosol chargers, an AC-corona (Electrical Ionizer 1090, MSP Corp.), a soft X-ray (Advanced Aerosol Neutralizer 3087, TSI Inc.), and an α-radiation-based 241Am charger (tapcon & analysesysteme), were investigated on their charging performance of airborne nanoparticles. The charging probabilities for negatively and positively charged particles and the particle size conservation were measured in the diameter range of 5-40 nm using sucrose nanoparticles. Chargers were operated under various flow conditions in the range of 0.6-5.0 liters per minute. For particular experimental conditions, some deviations from the chosen theoretical model were found for all chargers. For very small particle sizes, the AC-corona charger showed particle losses at low flow rates and did not reach steady-state charge equilibrium at high flow rates. However, for all chargers, operating conditions were identified where the bipolar charge equilibrium was achieved. Practically, excellent particle size conservation was found for all three chargers.

  19. Treatment of airborne asbestos and asbestos-like microfiber particles using atmospheric microwave air plasma.

    PubMed

    Averroes, A; Sekiguchi, H; Sakamoto, K

    2011-11-15

    Atmospheric microwave air plasma was used to treat asbestos-like microfiber particles that had two types of ceramic fiber and one type of stainless fiber. The treated particles were characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). The experiment results showed that one type of ceramic fiber (Alumina:Silica=1:1) and the stainless fiber were spheroidized, but the other type of ceramic fiber (Alumina:Silica=7:3) was not. The conversion of the fibers was investigated by calculating the equivalent diameter, the aspect ratio, and the fiber content ratio. The fiber content ratio in various conditions showed values near zero. The relationship between the normalized fiber vanishing rate and the energy needed to melt the particles completely per unit surface area of projected particles, which is defined as η, was examined and seen to indicate that the normalized fiber vanishing rate decreased rapidly with the increase in η. Finally, some preliminary experiments for pure asbestos were conducted, and the analysis via XRD and phase-contrast microscopy (PCM) showed the availability of the plasma treatment.

  20. Personal exposure to airborne ultrafine particles in the urban area of Milan

    NASA Astrophysics Data System (ADS)

    Cattaneo, A.; Garramone, G.; Taronna, M.; Peruzzo, C.; Cavallo, D. M.

    2009-02-01

    The relevance of health effects related to ultrafine particles (UFPs; aerodynamic diameter < 100 nm) can be better evaluated using high-resolution strategies for measuring particle number concentrations. In this study, two different portable Condensation Particle Counters (CPCs) were used to measure personal exposure to UFPs in the central area of Milan for one week period during spring, with three sampling sessions per day. Experimental data were continuously collected along an established urban pathway, moving afoot or by different private and public means of transport. Correlation analysis between data measured by two CPCs was performed and general results showed a good agreement, especially at concentrations lower than 2×105 particles /cm3. UFPs measures were divided on the basis of crossed environments or micro-environments, days of the week and day time (hours). The highest measured mean concentrations and data variability were observed during walking time and moving on motorized vehicles (bus and car), indicating that the highest exposure to UFPs can be reached near motorized traffic. The lowest exposures were observed in green areas and in office microenvironments. An appreciable difference between working and non-working days was observed. Concentration patterns and variation by days of the week and time periods appears related to time trends in traffic intensity.

  1. Calibration and demonstration of a condensation nuclei counting system for airborne measurements of aircraft exhausted particles

    NASA Astrophysics Data System (ADS)

    Cofer, Wesley R.; Anderson, Bruce E.; Winstead, Edward L.; Bagwell, Donald R.

    A system of multiple continuous-flow condensation nuclei counters (CNC) was assembled, calibrated, and demonstrated on a NASA T-39 Sabreliner jet aircraft. The mission was to penetrate the exhaust plumes and/or contrails of other subsonic jet aircraft and determine the concentrations of submicrometer diameter aerosol particles. Mission criteria required rapid response measurements ( ˜ 1 s) at aircraft cruise altitudes (9-12 km). The CNC sampling system was optimized to operate at 160 Torr. Aerosol samples were acquired through an externally mounted probe. Installed downstream of the probe was a critical flow orifice that provided sample to the CNC system. The orifice not only controlled volumetric flow rate, but also dampened probe pressure/flow oscillations encountered in the turbulent aircraft-wake vortex environment. Laboratory calibrations with NaCl particles under representative conditions are reported that indicate small amounts of particle loss and a maximum measurement efficiency of ˜ 75% for particles with diameters ranging from ⩾ 0.01- ⩽ 0.18 μm Data from exhaust/contrail samplings of a NASA B757 and DC-8 at cruise altitude are discussed. Data include exhaust/contrail measurements made during periods in which the B757 port jet engine burned low-sulfur fuel while the starboard engine simultaneously burned specially prepared high-sulfur fuel. The data discussed highlight the CNC systems performance, and introduce new observations pertinent to the behavior of sulfur in aircraft exhaust aerosol chemistry.

  2. The weather dependence of particle size distribution of indoor radioactive aerosol associated with radon decay products.

    PubMed

    Mostafa, A M A; Tamaki, K; Moriizumi, J; Yamazawa, H; Iida, T

    2011-07-01

    This study was performed to measure the activity size distribution of aerosol particles associated with short-lived radon decay products in indoor air at Nagoya University, Nagoya, Japan. The measurements were performed using a low pressure Andersen cascade impactor under variable meteorological conditions. The results showed that the greatest activity fraction was associated with aerosol particles in the accumulation size range (100-1000 nm) with a small fraction of nucleation mode (10-100 nm). Regarding the influence of the weather conditions, the decrease in the number of accumulation particles was observed clearly after rainfall without significant change in nucleation particles, which may be due to a washout process for the large particles.

  3. Airborne minerals and related aerosol particles: Effects on climate and the environment

    PubMed Central

    Buseck, Peter R.; Pósfai, Mihály

    1999-01-01

    Aerosol particles are ubiquitous in the troposphere and exert an important influence on global climate and the environment. They affect climate through scattering, transmission, and absorption of radiation as well as by acting as nuclei for cloud formation. A significant fraction of the aerosol particle burden consists of minerals, and most of the remainder— whether natural or anthropogenic—consists of materials that can be studied by the same methods as are used for fine-grained minerals. Our emphasis is on the study and character of the individual particles. Sulfate particles are the main cooling agents among aerosols; we found that in the remote oceanic atmosphere a significant fraction is aggregated with soot, a material that can diminish the cooling effect of sulfate. Our results suggest oxidization of SO2 may have occurred on soot surfaces, implying that even in the remote marine troposphere soot provided nuclei for heterogeneous sulfate formation. Sea salt is the dominant aerosol species (by mass) above the oceans. In addition to being important light scatterers and contributors to cloud condensation nuclei, sea-salt particles also provide large surface areas for heterogeneous atmospheric reactions. Minerals comprise the dominant mass fraction of the atmospheric aerosol burden. As all geologists know, they are a highly heterogeneous mixture. However, among atmospheric scientists they are commonly treated as a fairly uniform group, and one whose interaction with radiation is widely assumed to be unpredictable. Given their abundances, large total surface areas, and reactivities, their role in influencing climate will require increased attention as climate models are refined. PMID:10097046

  4. Work in progress: transcatheter embolization of renal cell carcinoma with radioactive infarct particles

    SciTech Connect

    Lang, E.K.; Sullivan, J.; DeKernion, J.B.

    1983-05-01

    Treatment by radioactive infarct implant is advocated for patients who have renal cell carcinoma with distant metastases. The radioactive infarct implants were placed into the primary tumor, and when feasible into metastases, by transcatheter embolization. Metastases to the skeleton, liver, lungs, adrenals, and retroperitoneal muscles were also seeded; metastases to the central nervous system, pancreas, and spleen, as well as most pulmonary metastases, proved inaccessible to this approach. The effectiveness of this treatment modality was shown by improved cumulative survival rates (59% for patients with metastases and at risk at two years and 50% for those at risk at five years). The best results were obtained when treating patients who had skeletal metastases (90% survival of those at risk at two years and 60% at five years). Measurable palliation factors, such as decrease in the size of the primary lesion, weight gain, and control of bleeding and pain, were indicators of treatment response and were observed in the majority of patients. Remissions were signaled by weight gain, normalization of the erythrocyte sedimentation rate, and disappearance or decrease of tumor markers. Some evidence suggests that the salutary results may be based on significant reduction of tumor burden, temporary local control of tumor, and improved general immunocompetence.

  5. TOF-SIMS measurements for toxic air pollutants adsorbed on the surface of airborne particles

    NASA Astrophysics Data System (ADS)

    Tomiyasu, Bunbunoshin; Hoshi, Takahiro; Owari, Masanori; Nihei, Yoshimasa

    2003-01-01

    Three kinds of particulate matter were collected: diesel and gasoline exhaust particles emitted directly from exhaust nozzle, and suspended particulate matter (SPM) near the traffic route. Soxhlet extraction was performed on each sample. By gas-chromatograph-mass spectrometer (GC-MS) analysis of these extracts, di-ethyl phthalate and di- n-butyl phthalate were detected from the extract of SPM and diesel exhaust particles (DEPs). Because these phthalates were sometimes suspected as contamination, time-of-flight secondary ion mass spectrometry (TOF-SIMS) measurements were also performed on the samples collected at the same environment. By comparing obtained spectra, it is clear that these environmental endocrine disrupters (EEDs) were adsorbed on DEP surface. Thus, we concluded that the combination of conventional method and TOF-SIMS measurement is one of the most powerful techniques for analyzing the toxic air pollutants adsorbed on SPM surface.

  6. The impact of particle size selective sampling methods on occupational assessment of airborne beryllium particulates.

    PubMed

    Sleeth, Darrah K

    2013-05-01

    In 2010, the American Conference of Governmental Industrial Hygienists (ACGIH) formally changed its Threshold Limit Value (TLV) for beryllium from a 'total' particulate sample to an inhalable particulate sample. This change may have important implications for workplace air sampling of beryllium. A history of particle size-selective sampling methods, with a special focus on beryllium, will be provided. The current state of the science on inhalable sampling will also be presented, including a look to the future at what new methods or technology may be on the horizon. This includes new sampling criteria focused on particle deposition in the lung, proposed changes to the existing inhalable convention, as well as how the issues facing beryllium sampling may help drive other changes in sampling technology.

  7. Measurement of Soluble and Total Hexavalent Chromium in the Ambient Airborne Particles in New Jersey

    PubMed Central

    Huang, Lihui; Yu, Chang Ho; Hopke, Philip K.; Lioy, Paul J.; Buckley, Brian T.; Shin, Jin Young; Fan, Zhihua (Tina)

    2015-01-01

    Hexavalent chromium (Cr(VI)) in ambient airborne particulate matter (PM) is a known pulmonary carcinogen and may have both soluble and insoluble forms. The sum of the two forms is defined as total Cr(VI). Currently, there were no methods suitable for large-scale monitoring of total Cr(VI) in ambient PM. This study developed a method to measure total Cr(VI) in ambient PM. This method includes PM collection using a Teflon filter, microwave extraction with 3% Na2CO3-2% NaOH at 95°C for 60 minutes, and Cr(VI) analysis by 1,5-diphenylcarbazide colorimetry at 540 nm. The recoveries of total Cr(VI) were 119.5 ± 10.4% and 106.3 ± 16.7% for the Cr(VI)-certified reference materials, SQC 012 and SRM 2700, respectively. Total Cr(VI) in the reference urban PM (NIST 1648a) was 26.0 ± 3.1 mg/kg (%CV = 11.9%) determined by this method. The method detection limit was 0.33 ng/m3. This method and the one previously developed to measure ambient Cr(VI), which is soluble in pH ~9.0 aqueous solution, were applied to measure Cr(VI) in ambient PM10 collected from three urban areas and one suburban area in New Jersey. The total Cr(VI) concentrations were 1.05–1.41 ng/m3 in the winter and 0.99–1.56 ng/m3 in the summer. The soluble Cr(VI) concentrations were 0.03–0.19 ng/m3 in the winter and 0.12–0.37 ng/m3 in the summer. The summer mean ratios of soluble to total Cr(VI) were 14.3–43.7%, significantly higher than 4.2–14.4% in the winter. The winter concentrations of soluble and total Cr(VI) in the suburban area were significantly lower than in the three urban areas. The results suggested that formation of Cr(VI) via atmospheric chemistry may contribute to the higher soluble Cr(VI) concentrations in the summer. PMID:26120324

  8. Use of micro-XANES to speciate chromium in airborne fine particles in the Sacramento Valley

    SciTech Connect

    Michelle L. Werner; Peter S. Nico; Matthew A. Marcus; Cort Anastasio

    2007-07-15

    While particulate matter (PM) in the atmosphere can lead to a wide array of negative health effects, the cause of toxicity is largely unknown. One aspect of PM that likely affects health is the chemical composition, in particular the transition metals within the particles. Chromium is one transition metal of interest due to its two major oxidation states, with Cr(III) being much less toxic compared to Cr(VI). Using microfocused X-ray absorption near edge structure (micro-XANES), we analyzed the Cr speciation in fine particles (diameters {le} 2.5 {mu}m) collected at three sites in the Sacramento Valley of northern California: Sacramento, a large urban area, Davis, a small city, and Placerville, a rural area. These are several major stationary sources of Cr within 24 km of the site including chrome-plating plants, power plants and incinerators. The microfocused X-ray beam enables us to look at very small areas on the filter with a resolution of typically 5-7 micrometers. With XANES we are able to not only distinguish between Cr(VI) and Cr(III), but also to identify different types of Cr(III) and more reduced Cr species. At all of our sampling sites the main Cr species were Cr(III), with Cr(OH){sub 3} or a Cr-Fe, chromite-like, phase being the dominant species. Cr(VI)-containing particles were found only in the most urban site. All three sites contained some reduced Cr species, either Cr(0) or Cr{sub 3}C{sub 2}, although these were minor components. This work demonstrates that micro-XANES can be used as a minimally invasive analytical tool to investigate the composition of ambient PM. 32 refs., 6 figs.

  9. Distinguishing nanomaterial particles from background airborne particulate matter for quantitative exposure assessment

    NASA Astrophysics Data System (ADS)

    Ono-Ogasawara, Mariko; Serita, Fumio; Takaya, Mitsutoshi

    2009-10-01

    As the production of engineered nanomaterials quantitatively expands, the chance that workers involved in the manufacturing process will be exposed to nanoparticles also increases. A risk management system is needed for workplaces in the nanomaterial industry based on the precautionary principle. One of the problems in the risk management system is difficulty of exposure assessment. In this article, examples of exposure assessment in nanomaterial industries are reviewed with a focus on distinguishing engineered nanomaterial particles from background nanoparticles in workplace atmosphere. An approach by JNIOSH (Japan National Institute of Occupational Safety and Health) to quantitatively measure exposure to carbonaceous nanomaterials is also introduced. In addition to real-time measurements and qualitative analysis by electron microscopy, quantitative chemical analysis is necessary for quantitatively assessing exposure to nanomaterials. Chemical analysis is suitable for quantitative exposure measurement especially at facilities with high levels of background NPs.

  10. Field comparison of instruments for exposure assessment of airborne ultrafine particles and particulate matter

    NASA Astrophysics Data System (ADS)

    Spinazzè, Andrea; Fanti, Giacomo; Borghi, Francesca; Del Buono, Luca; Campagnolo, Davide; Rovelli, Sabrina; Cattaneo, Andrea; Cavallo, Domenico M.

    2017-04-01

    The objective of this study was to compare the use of co-located real-time devices and gravimetric samplers to measure ultrafine particles (UFP) and size-fractionated PM mass concentrations. The results contribute to evaluating the comparability of different monitoring instruments for size-fractionated PM concentrations. Paired light scattering devices and gravimetric samplers were used to measure the PM1, PM2.5, PM4/5, PM10 and TSP mass concentrations during 8-h monitoring sessions in an urban background site (Como, Italy) in winter. A total of 16 sampling sessions were performed: measurements were analyzed using linear regression analysis. Absolute deviations between techniques were calculated and discussed. The UFP concentrations measured using a condensation particle counter were clearly overestimated compared with the reference instrument (portable diffusion charger), with an absolute deviation that appeared to increase with the UFP concentration. The comparison of different light-scattering devices (photometers - 'PHOTs') indicated an over-estimation of two of the tested instruments (PHOT-2 and PHOT-3) with respect to the one used as the reference (PHOT-1) regarding the measurement of the size-fractioned PM, with the only exception being PM4/5. Further, the comparison of different light-scattering devices with filter-based samplers indicated that direct-reading devices tend to over-estimate (PHOT-2, PHOT-3) or under-estimate (PHOT-1) the PM concentrations from gravimetric analysis. The comparison of different filter-based samplers showed that the observed over-estimation error increased with increasing PM concentration levels; however, the good level of agreement between the investigated methods allowed them to be classified as comparable, although they cannot be characterized as having reciprocal predictability. Ambient relative humidity was correlated with the absolute error resulting from the comparison of direct-reading vs. filter-based techniques, as

  11. Measurement of resuspended aerosol in the Chernobyl area. Part III. Size distribution and dry deposition velocity of radioactive particles during anthropogenic enhanced resuspension.

    PubMed

    Garger, E K; Paretzke, H G; Tschiersch, J

    1998-10-01

    During anthropogenic activities, such as agricultural soil management and traffic on unpaved roads, size distribution measurements were performed of atmospheric particulate radionuclides at a site in the Chernobyl 30-km exclusion zone. Analysis of cascade impactor measurements showed an increase of the total atmospheric radioactivity. In the cases of harrowing by a tractor and traffic on unpaved roads, a common shape of the size distribution was found with two maxima, the first in the 2-4 microm range, the second in the 12-20 microm range. The size distributions were compared to measurements during wind-driven resuspension. Particle number concentration measurements with an Aerodynamic Particle Sizer showed a dynamic dependence of the particle concentration in different size ranges on anthropogenic action. The increase of the mean concentration was for the large particles more than one order of magnitude higher than for fine particles during anthropogenic enhanced resuspension. From the measurement of the mass concentration, the radioactive loading could be estimated. An enrichment of radionuclides on resuspended particles (compared to soil particles) was found, with the highest enrichment for large particles. Micrometeorological considerations showed that large particles may frequently be subject to medium range transport. The dry deposition velocity was measured; the mean value of 0.026 m s(-1) +/- 0.016 m s(-1) is typical for 6-9 microm diameter particles.

  12. Nucleon-Alpha Particle Disequilibrium and Short-Lived r-Process Radioactivities

    NASA Technical Reports Server (NTRS)

    Meyer, B. S.; Clayton, D. D.; Chellapilla, S.; The, L.-S.

    2002-01-01

    r-Process yields can be extremely sensitive to expansion parameters when a persistent disequilibrium between free nucleons and alpha particles is present. This may provide a natural scenario for understanding the variation of heavy and light r-process isotopes in different r-process events. Additional information is contained in the original extended abstract.

  13. Effect of using nano and micro airborne abrasive particles on bond strength of implant abutment to prosthesis.

    PubMed

    Rismanchian, Mansour; Davoudi, Amin; Shadmehr, Elham

    2015-01-01

    Connecting prostheses to the implant abutments has become a concern and achieving a satisfactory retention has been focused in cement-retention prostheses recently. Sandblasting is a method to make a roughened surface for providing more retention. The aim of this study was to compare effects of nano and micro airborne abrasive particles (ABAP) in roughening surface of implant abutments and further retention of cemented copings. Thirty Xive abutments and analogues (4.5 D GH1) were mounted vertically in self-cured acrylic blocks. Full metal Ni-Cr copings with a loop on the top were fabricated with appropriate marginal adaptation for each abutment. All samples were divided into 3 groups: first group (MPS) was sandblasted with 50 µm Al2O3 micro ABAP, second group (NSP) was sandblasted with 80 nm Al2O3 nano ABAP, and the third group (C) was assumed as control. The samples were cemented with provisional cement (Temp Bond) and tensile bond strength of cemented copings was evaluated by a universal testing machine after thermic cycling. The t test for independent samples was used for statistical analysis by SPSS software (version 15) at the significant level of 0.05. Final result showed significant difference among all groups (p<0.001) and MPS manifested the highest mean retention (207.88 ± 45.61 N) with significant difference among other groups (p<0.001). The control group showed the lowest bond strength as predicted (48.95 ± 10.44 N). Using nano or micro ABAP is an efficient way for increasing bond strengths significantly, but it seems that micro ABAP was more effective.

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

    PubMed

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

    2014-08-01

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

  15. Indoor-outdoor relationships of airborne particles and nitrogen dioxide inside Parisian buses

    NASA Astrophysics Data System (ADS)

    Molle, Romain; Mazoué, Sophie; Géhin, Évelyne; Ionescu, Anda

    2013-04-01

    This study evaluated passengers' exposure to traffic air pollution inside the articulated buses of the line 91 in Paris during 10 working days in May, 2010. Twenty articulated buses were studied on 32 routes in order to determine the influence of the sampling position on the pollutant concentrations. This parameter is still poorly known for the rigid buses and is even less known for the articulated ones. However this parameter must be studied for articulated buses because the greater length may cause a pollutant concentration gradient in the cabin. Portable devices were used to measure pollutants in the presence of passengers from 8 a.m. to 9 a.m. and from 4 p.m. to 5 p.m., time periods corresponding to the peak traffic and travellers. PM2.5 mass concentration, particle number concentration between 0.3 and 20 μm and nitrogen dioxide concentration were simultaneously measured on three positions inside the buses (front, middle and rear) in order to study the spatial distribution of these compounds. These measurements inside the buses were compared to the outdoor concentrations at the same moment of the day provided by the Parisian air quality monitoring network; they were also compared to the results of a previous monitoring campaign performed in 2008. The results obtained during the 2010 campaign revealed that in-cabin NO2 mean concentrations were 1.5-3.5 times higher than the outside concentration levels; a maximum concentration of 234 ± 40 μg m-3 was found in the rear position (location of the engine and exhaust gas). Mean in-cabin PM2.5 mass concentrations varied from one week to another one, but they were globally the same at the three positions inside the instrumented buses. In order to determine the impact of outdoor levels, correlations have been calculated between the results measured inside the buses and those measured by the outdoor air monitoring stations. The highest Pearson correlation coefficient was 0.29 for NO2 data whereas the highest Pearson

  16. Induced radioactivities in concrete constituents irradiated by high-energy particles.

    PubMed

    Kondo, K; Hirayama, H; Ban, S; Taino, M; Ishii, H

    1984-06-01

    The powdered concrete constituents of magnetite ore, pyrites ore, marble, gravel and Portland cement were prepared and irradiated by 12- GeV protons and secondary particles at the slow extracted beam line of the National Laboratory for High Energy Physics ( KEK ) 12- GeV proton synchrotron. The saturated activities for individual nuclides produced were calculated, and the time variation of photon exposure rate due to the residual activities was also evaluated for each sample. The exposure rates ranked in the following order: magnetite ore greater than pyrites ore greater than gravel greater than or equal to cement greater than marble. The levels of photon exposure rates from heavy, ordinary and marble concretes were also estimated on the basis of the results obtained for each constituent. It is suggested that the use of marble concrete in the inside wall of accelerator tunnels can reduce considerably the exposure to the accelerator maintenance workers, compared with heavy and ordinary concretes commonly used.

  17. Experimental detection of alpha-particles from the radioactive decay of natural bismuth.

    PubMed

    de Marcillac, Pierre; Coron, Noël; Dambier, Gérard; Leblanc, Jacques; Moalic, Jean-Pierre

    2003-04-24

    The only naturally occurring isotope of bismuth, 209Bi, is commonly regarded as the heaviest stable isotope. But like most other heavy nuclei abundant in nature and characterized by an exceptionally long lifetime, it is metastable with respect to alpha-decay. However, the decay usually evades observation because the nuclear structure of 209Bi gives rise to an extremely low decay probability and, moreover, generates low-energy alpha-particles difficult to detect. Indeed, dedicated experiments attempting to record the alpha-decay of 209Bi in nuclear emulsions failed. However, scintillating bolometers operated at temperatures below 100 mK offer improved detection efficiency and sensitivity, whereas a broad palette of targets could be available. Here we report the successful use of this method for the unambiguous detection of 209Bi alpha-decay in bismuth germanate detectors cooled to 20 mK. We measure an energy release of 3,137 +/- 1 (statistical) +/- 2 (systematic) keV and a half-life of (1.9 +/- 0.2) x 10(19) yr, which are in agreement with expected values.

  18. Heavy particle radioactivity from superheavy nuclei leading to 298114 daughter nuclei

    NASA Astrophysics Data System (ADS)

    Santhosh, K. P.; Priyanka, B.

    2014-09-01

    The feasibility for the alpha decay and the heavy particle decay from the even-even superheavy (SH) nuclei with Z = 116- 124 has been studied within the Coulomb and proximity potential model (CPPM). Our predicted half lives agree well with the values evaluated using the Universal formula for cluster decay (UNIV) of Poenaru et al., the Universal Decay Law (UDL) of Qi et al., and the Scaling Law of Horoi et al. The spontaneous fission half lives of the corresponding parents have also been evaluated using the semi-empirical formula of Santhosh et al. Within our fission model, we have studied the cluster formation probability for various clusters and the maximum cluster formation probability is found for the decay accompanying 298114. In the plots for log10 (T1/2) against the neutron number of the daughter in the corresponding decay, the half life is found to be the minimum for the decay leading to 298114 (Z = 114, N = 184). Most of the predicted half lives are well within the present upper limit for measurements (T1/2 <1030 s) and the computed alpha half lives for 290,292Lv agree well with the experimental data.

  19. Measurement of airborne gunshot particles in a ballistics laboratory by sector field inductively coupled plasma mass spectrometry.

    PubMed

    Diaz, Ernesto; Sarkis, Jorge E Souza; Viebig, Sônia; Saldiva, Paulo

    2012-01-10

    The present study aimed determines lead (Pb), antimony (Sb) and barium (Ba) as the major elements present in GSR in the environmental air of the Ballistics Laboratory of the São Paulo Criminalistics Institute (I.C.-S.P.), São Paulo, SP, Brazil. Micro environmental monitors (mini samplers) were located at selected places. The PM(2.5) fraction of this airborne was collected in, previously weighted filters, and analyzed by sector field inductively coupled plasma mass spectrometer (SF-HR-ICP-MS). The higher values of the airborne lead, antimony and barium, were found at the firing range (lead (Pb): 58.9 μg/m(3); barium (Ba): 6.9 μg/m(3); antimony (Sb): 7.3 μg/m(3)). The mean value of the airborne in this room during 6 monitored days was Pb: 23.1 μg/m(3); Ba: 2.2 μg/m(3); Sb: 1.5 μg/m(3). In the water tank room, the air did not show levels above the limits of concern. In general the airborne lead changed from day to day, but the barium and antimony remained constant. Despite of that, the obtained values suggest that the workers may be exposed to airborne lead concentration that can result in an unhealthy environment and could increase the risk of chronic intoxication.

  20. Radioactive Iodine

    MedlinePlus

    ... Phone Home » Radioactive Iodine Leer en Español Radioactive Iodine Iodine is essential for proper function of the ... that takes up and holds onto iodine. Radioactive Iodine FAQs WHAT IS RADIOACTIVE IODINE (RAI)? Iodine, in ...

  1. Organic compounds present in airborne particles stimulate superoxide production and DNA fragmentation: role of NOX and xanthine oxidase in animal tissues.

    PubMed

    Busso, Iván Tavera; Silva, Guillermo Benjamín; Carreras, Hebe Alejandra

    2016-08-01

    Suspended particulate matter trigger the production of reactive oxygen species. However, most of the studies dealing with oxidative damage of airborne particles focus on the effects of individual compounds and not real mixtures. In order to study the enzymatic superoxide production resulting from the exposition to a complex mixture, we derived organic extracts from airborne particles collected daily in an urban area and exposed kidney, liver, and heart mammal tissues. After that, we measured DNA damage employing the comet assay. We observed that in every tissue, NADPH oxidase and xanthine oxidase were involved in O2 (-) production when they were exposed to the organic extracts, as the lucigenin's chemiluminescence decays when enzymes were inhibited. The same trend was observed with the percentage of cells with comets, since DNA damage was higher when they were exposed to same experimental conditions. Our data allow us to hypothesize that these enzymes play an important role in the oxidative stress produced by PAHs and that there is a mechanism involving them in the O2 (-)generation.

  2. Combined MIPAS (airborne/satellite), CALIPSO and in situ study on large potential NAT particles observed in early Arctic winter stratosphere in December 2011

    NASA Astrophysics Data System (ADS)

    Woiwode, Wolfgang; Höpfner, Michael; Pitts, Michael; Poole, Lamont; Oelhaf, Hermann; Molleker, Sergej; Borrmann, Stephan; Ebersoldt, Andreas; Frey, Wiebke; Gulde, Thomas; Maucher, Guido; Piesch, Christof; Sartorius, Christian; Orphal, Johannes

    2015-04-01

    The understanding of the characteristics of large HNO3-containing particles (potential 'NAT-rocks') involved in vertical redistribution of HNO3 in the polar winter stratosphere is limited due to the difficult accessibility of these particles by observations. While robust polar stratospheric cloud (PSC) classification schemes exist for observations by the space-borne lidar aboard CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) as well as for the passive mid-infrared limb observations by MIPAS (Michelson Interferometer for Passive Atmospheric Sounding), these observations are hardly exploited for the detection of large (diameter >10 μm) NAT particles. This is due to the facts that these particles have low overall number densities, resulting in weak detectable signatures, and that the physical characteristics of these particles (i.e. shape, morphology, HNO3-content and optical characteristics) are uncertain. We investigate collocated and complementary observations of a low-density potential large NAT particle field by the space-borne instruments CALIPSO and MIPAS-ENVISAT as well as the airborne observations by the limb-sounder MIPAS-STR and the in situ particle probe FSSP-100 (Forward Scattering Spectrometer Probe 100) aboard the high-altitude aircraft Geophysica. The observations aboard the Geophysica on 11 December 2011 associated to ESSenCe (ESa Sounder Campaign 2011) provided us the unique opportunity to study in detail the lower boundary region of a PSC where large potential NAT particles (>20 μm in diameter) were detected in situ. We analyse the ambient temperatures and gas-phase composition (HNO3 and H2O), the signatures of the observed particles in the CALIPSO and MIPAS observations, the HNO3-content of these particles suggested by the FSSP-100 and MIPAS-STR observations, and focus on the spectral fingerprint of these particles in the MIPAS-STR observations. While the spectral characterisation of the observed particles is subject

  3. Observations of urban airborne particle number concentrations during rush-hour conditions: analysis of the number based size distributions and modal parameters.

    PubMed

    Lingard, Justin J N; Agus, Emily L; Young, David T; Andrews, Gordon E; Tomlin, Alison S

    2006-12-01

    A summertime study of the number concentration and the size distribution of combustion derived nanometre sized particles (termed nanoparticles) from diesel and spark-ignition (SI) engine emissions were made under rush-hour and free-flow traffic conditions at an urban roadside location in Leeds, UK in July 2003. The measured total particle number concentrations (N(TOTAL)) were of the order 1.8 x 10(4) to 3.4 x 10(4) cm(-3), and tended to follow the diurnal traffic flow patterns. The N(TOTAL) was dominated by particles < or =100 nm in diameter which accounted for between 89-93% of the measured particle number. By use of a log-normal fitting procedure, the modal parameters of the number based particle size distribution of urban airborne particulates were derived from the roadside measurements. Four component modes were identified. Two nucleation modes were found, with a smaller, more minor, mode composed principally of sub-11 nm particles, believed to be derived from particles formed from the nucleation of gaseous species in the atmosphere. A second mode, much larger in terms of number, was composed of particles within the size range of 10-20 nm. This second mode was believed to be principally derived from the condensation of the unburned fuel and lube oil (the solvent organic fraction or SOF) as it cooled on leaving the engine exhaust. Third and fourth modes were noted within the size ranges of 28-65 nm and 100-160 nm, respectively. The third mode was believed to be representative of internally mixed Aitken mode particles composed of a soot/ash core with an adsorbed layer of readily volatilisable material. The fourth mode was believed to be composed of chemically aged, secondary particles. The larger nucleation and Aitken modes accounted for between 80-90% of the measured N(TOTAL), and the particles in these modes were believed to be derived from SI and diesel engine emissions. The overall size distribution, particularly in modes II-IV, was observed to be strongly

  4. Airborne Coarse Mode Aerosol Measurements with the CAS-DPOL Instrument: Effects of Particle Shape and Refractive Index and Implications for Radiative Transfer Estimate

    NASA Astrophysics Data System (ADS)

    Sauer, D. N.; Weinzierl, B.; Gasteiger, J.; Spanu, A.; Freudenthaler, V.; Gross, S.

    2015-12-01

    Each year huge amounts of mineral dust are mobilized in deserts and arid regions of the world and transported over large distances forming thick elevated aerosol layers with a substantial fraction of coarse mode particles. Optical properties of mineral dust, including the absorptive refractive index of some components, cause a significant effect on the atmospheric radiative energy balance from optical to infrared wavelengths. The aerosol characteristics, in particular its coarse mode size distribution, are modified during long-range transport by aging and deposition processes. This also affects the aerosol optical properties and therefore the effect on the atmospheric radiative energy budget. In-situ measurements of aerosol microphysical properties are essential to characterize those effects in order to be implemented in global climate models in parametrized form. However, in-situ measurements of airborne coarse mode aerosols such as mineral dust and volcanic ash are challenging and the measurements are usually affected by substantial uncertainties. In this work we use airborne measurements of mineral dust from our optical light-scattering spectrometer CAS-DPOL during SALTRACE 2013 to discuss the analysis of such data. We cover the effects of varying refractive index and particle shapes and develop recommendations for the configuration of the CAS-DPOL for aerosol studies. We also present an inversion method to derive coarse mode size distributions from light-scattering probes for mixtures of non-spherical, absorbing aerosols. The size distributions retrieved from the in-situ measurements are then validated using an independent analysis with a combination of sun-photometer and lidar data. We apply these methods to investigate the Saharan mineral dust particle size distributions measured on both sides of the Atlantic Ocean and discuss the influence of aerosol aging on the atmospheric radiative energy budget. With this example we also assess how the uncertainties

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

    NASA Astrophysics Data System (ADS)

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

    2013-06-01

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

  6. Vertical wind retrieved by airborne lidar and analysis of island induced gravity waves in combination with numerical models and in situ particle measurements

    NASA Astrophysics Data System (ADS)

    Chouza, Fernando; Reitebuch, Oliver; Jähn, Michael; Rahm, Stephan; Weinzierl, Bernadett

    2016-04-01

    This study presents the analysis of island induced gravity waves observed by an airborne Doppler wind lidar (DWL) during SALTRACE. First, the instrumental corrections required for the retrieval of high spatial resolution vertical wind measurements from an airborne DWL are presented and the measurement accuracy estimated by means of two different methods. The estimated systematic error is below -0.05 m s-1 for the selected case of study, while the random error lies between 0.1 and 0.16 m s-1 depending on the estimation method. Then, the presented method is applied to two measurement flights during which the presence of island induced gravity waves was detected. The first case corresponds to a research flight conducted on 17 June 2013 in the Cabo Verde islands region, while the second case corresponds to a measurement flight on 26 June 2013 in the Barbados region. The presence of trapped lee waves predicted by the calculated Scorer parameter profiles was confirmed by the lidar and in situ observations. The DWL measurements are used in combination with in situ wind and particle number density measurements, large-eddy simulations (LES), and wavelet analysis to determine the main characteristics of the observed island induced trapped waves.

  7. Radioactive Decay

    EPA Pesticide Factsheets

    Radioactive decay is the emission of energy in the form of ionizing radiation. Example decay chains illustrate how radioactive atoms can go through many transformations as they become stable and no longer radioactive.

  8. Mutagenicity and polycyclic aromatic hydrocarbons associated with extractable organic matter from airborne particles ⩽10 μm in southwest Mexico City

    NASA Astrophysics Data System (ADS)

    Villalobos-Pietrini, Rafael; Amador-Muñoz, Omar; Waliszewski, Stefan; Hernández-Mena, Leonel; Munive-Colín, Zenaida; Gómez-Arroyo, Sandra; Bravo-Cabrera, José Luis; Frías-Villegas, Alejandro

    A year-long sampling and analysis of 24 h airborne particles equal to or less than 10 μm (PM 10) was conducted in Southwest (SW) Mexico City in 1998. The amount of airborne PM 10 and its extractable organic matter (EOM) were highly correlated. The year 1998 was particularly dry with many fires, and higher values of PM 10 and EOM were obtained in the fire period (February-May) compared to the without fire period (January, June-December). The indirect-acting mutagenicity ( Salmonella typhimurium strain TA98 with mammalian metabolic activation, S9) did not correlate with the monthly concentrations of PM 10 and EOM, while the direct-acting mutagenicity (strains TA98 and YG1021, without mammalian metabolic activation) did correlate. The highest monthly mutagenic potency of TA98+S9 and of TA98-S9 were registered in May which correspond to the fire period, while for YG1021 the highest was in December, a without fire month. The highest TA98+S9/TA98-S9 ratios appeared from April to September (with the exception of June), indicating that emission of the direct mutagens occurred in the rest of the year (the coldest months), and December showed the highest mutagenicity of YG1021. The correlation of this mutagenicity with the number of ground-based inversions indicated a greater emissions of nitroarenes in the coldest months emitted mainly by vehicular traffic as shown by the correlation between YG1021 with CO and with NO 2. We did not find a correlation in the EOM of the complex mixtures between TA98+S9 and the total concentration of polycyclic aromatic hydrocarbons (PAH) nor between TA98+S9 and specific PAH. The analysis by gas chromatography/mass spectrometry indicated the presence of retene, a PAH found in the fire period and considered a softwood burning marker. The concentrations of fluoranthene and benz[ a]anthracene correlated with that of retene and with the burned area; they were the only PAH that presented significant differences between the periods with fire and

  9. Combined scanning electron microscopy and image analysis to investigate airborne submicron particles: a comparison between personal samplers.

    PubMed

    Zamengo, L; Barbiero, N; Gregio, M; Orrù, G

    2009-07-01

    The main objectives of this study were: (i) to compare commonly used personal samplers and verify their collection efficiency with regards to submicron particles; (ii) to investigate how the submicron particles deposit onto the filter surface in order to assess the homogeneity of the deposition; (iii) to estimate the biases which could affect results when number concentration values have to be determined by particle counting. A method based on image analysis (IA) and scanning electron microscopy (SEM) is developed and adopted to investigate a large numbers of particles. Four different personal samplers were tested: the IOM sampler, the Button sampler and the German GSP for the inhalable aerosol fraction; the PEM sampler for the thoracic aerosol fraction. In order to investigate how particles distribute on the filters surface, the area of each filter was virtually divided into circular concentric areas or deposition zones (DZ). Results from different DZ of the same filter were compared. Uniformity of deposition was mostly observed for three of the four tested samplers. A significant radial distribution was observed only for the GSP sampler. The major homogeneity was found for the Button sampler. In order to estimate the relative collection efficiency between samplers, particles number concentrations determined by particle counting were compared. The GSP sampler provided the greatest concentrations but also the greatest variability. The PEM sampler provided the lowest concentrations. The homogeneity of particle deposition on the filter surface mostly affected results when counting is performed on localized areas of the filter.

  10. Optical pulling of airborne absorbing particles and smut spores over a meter-scale distance with negative photophoretic force

    SciTech Connect

    Lin, Jinda; Hart, Adam G.; Li, Yong-qing

    2015-04-27

    We demonstrate optical pulling of single light-absorbing particles and smut spores in air over a meter-scale distance using a single collimated laser beam based on negative photophoretic force. The micron-sized particles are pulled towards the light source at a constant speed of 1–10 cm/s in the optical pulling pipeline while undergoing transverse rotation at 0.2–10 kHz. The pulled particles can be manipulated and precisely positioned on the entrance window with an accuracy of ∼20 μm, and their chemical compositions can be characterized with micro-Raman spectroscopy.

  11. Apparatuses and methods for detecting, identifying and quantitating radioactive nuclei and methods of distinguishing neutron stimulation of a radiation particle detector from gamma-ray stimulation of a detector

    DOEpatents

    Cole, Jerald D.; Drigert, Mark W.; Reber, Edward L.; Aryaeinejad, Rahmat

    2001-01-01

    In one aspect, the invention encompasses a method of detecting radioactive decay, comprising: a) providing a sample comprising a radioactive material, the radioactive material generating decay particles; b)providing a plurality of detectors proximate the sample, the detectors comprising a first set and a second set, the first set of the detectors comprising liquid state detectors utilizing liquid scintillation material coupled with photo tubes to generate a first electrical signal in response to decay particles stimulating the liquid scintillation material, the second set of the detectors comprising solid state detectors utilizing a crystalline solid to generate a second electrical signal in response to decay particles stimulating the crystalline solid; c) stimulating at least one of the detectors to generate at least one of the first and second electrical signals, the at least one of the first and second electrical signals being indicative of radioactive decay in the sample. In another aspect, the invention encompasses an apparatus for identifying and quantitating radioactive nuclei of a sample comprising radioactive material that decays to generate neutrons and high-energy .gamma.-rays.

  12. Uptake of HNO3 to deliquescent sea-salt particles: a study using the short-lived radioactive isotope tracer 13N

    NASA Astrophysics Data System (ADS)

    Guimbaud, C.; Arens, F.; Gutzwiller, L.; Gäggeler, H. W.; Ammann, M.

    2002-10-01

    The uptake of HNO3 to deliquescent airborne sea-salt particles (RH = 55%, P = 760 torr, T = 300 K) at concentrations from 2 to 575 ppbv is measured in an aerosol flow tube using 13N as a tracer. Small particles ( 70 nm diameter) are used in order to minimize the effect of diffusion in the gas phase on the mass transfer. Below 100 ppbv, an uptake coefficient (gupt) of 0.50 ± 0.20 is derived. At higher concentrations, the uptake coefficient decreases along with the consumption of aerosol chloride. Data interpretation is further supported by using the North American Aerosol Inorganics Model (AIM), which predicts the aqueous phase activities of ions and the gas-phase partial pressures of H2O, HNO3, and HCl at equilibrium for the NaCl/HNO3/H2O system. These simulations show that the low concentration data are obtained far from equilibrium, which implies that the uptake coefficient derived is equal to the mass accommodation coefficient under these conditions. The observed uptake coefficient can serve as input to modeling studies of atmospheric sea-salt aerosol chemistry. The main sea-salt aerosol burden in the marine atmosphere is represented by coarse mode particles (> 1 µm diameter). This implies that diffusion in the gas-phase is the limiting step to HNO3 uptake until the sea-salt has been completely processed.

  13. Airborne measurements of new particle formation in the free troposphere above the Mediterranean Sea during the HYMEX campaign

    NASA Astrophysics Data System (ADS)

    Rose, C.; Sellegri, K.; Freney, E.; Dupuy, R.; Colomb, A.; Pichon, J.-M.; Ribeiro, M.; Bourianne, T.; Burnet, F.; Schwarzenboeck, A.

    2015-09-01

    While atmospheric new particle formation (NPF) has been observed in various environments and was found to contribute significantly to the total aerosol particle concentration, the production of new particles over open seas is poorly documented in the literature. Nucleation events were detected and analysed over the Mediterranean Sea using two condensation particle counters and a scanning mobility particle sizer on board the ATR-42 research aircraft during flights conducted between 11 September and 4 November 2012 in the framework of the HYMEX (HYdrological cycle in Mediterranean EXperiment) project. The main purpose of the present work was to characterize the spatial extent of the NPF process, both horizontally and vertically. Our findings show that nucleation is occurring over large areas above the Mediterranean Sea in all air mass types. Maximum concentrations of particles in the size range 5-10 nm (N5-10) do not systematically coincide with lower fetches (time spent by the air mass over the sea before sampling), and significant N5-10 values are found for fetches between 0 and 60 h depending on the air mass type. These observations suggest that nucleation events could be more influenced by local precursors originating from emission processes occurring above the sea, rather than linked to synoptic history. Vertical soundings were performed, giving the opportunity to examine profiles of the N5-10 concentration and to analyse the vertical extent of NPF. Our observations demonstrate that the process could be favoured above 1000 m, i.e. frequently in the free troposphere, and more especially between 2000 and 3000 m, where the NPF frequency is close to 50 %. This vertical distribution of NPF might be favoured by the gradients of several atmospheric parameters, together with the mixing of two air parcels, which could also explain the occurrence of the process at preferential altitudes. In addition, increased condensation sinks collocated with high concentrations of

  14. Performance of a scanning mobility particle sizer in measuring diverse types of airborne nanoparticles: Multi-walled carbon nanotubes, welding fumes, and titanium dioxide spray.

    PubMed

    Chen, Bean T; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-07-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the "gold standard" for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing "monodisperse" aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in some test

  15. Performance of a Scanning Mobility Particle Sizer in Measuring Diverse Types of Airborne Nanoparticles: Multi-Walled Carbon Nanotubes, Welding Fumes, and Titanium Dioxide Spray

    PubMed Central

    Chen, Bean T.; Schwegler-Berry, Diane; Cumpston, Amy; Cumpston, Jared; Friend, Sherri; Stone, Samuel; Keane, Michael

    2016-01-01

    Direct-reading instruments have been widely used for characterizing airborne nanoparticles in inhalation toxicology and industrial hygiene studies for exposure/risk assessments. Instruments using electrical mobility sizing followed by optical counting, e.g., scanning or sequential mobility particle spectrometers (SMPS), have been considered as the “gold standard” for characterizing nanoparticles. An SMPS has the advantage of rapid response and has been widely used, but there is little information on its performance in assessing the full spectrum of nanoparticles encountered in the workplace. In this study, an SMPS was evaluated for its effectiveness in producing “monodisperse” aerosol and its adequacy in characterizing overall particle size distribution using three test aerosols, each mimicking a unique class of real-life nanoparticles: singlets of nearly spherical titanium dioxide (TiO2), agglomerates of fiber-like multi-walled carbon nanotube (MWCNT), and aggregates that constitutes welding fume (WF). These aerosols were analyzed by SMPS, cascade impactor, and by counting and sizing of discrete particles by scanning and transmission electron microscopy. The effectiveness of the SMPS to produce classified particles (fixed voltage mode) was assessed by examination of the resulting geometric standard deviation (GSD) from the impactor measurement. Results indicated that SMPS performed reasonably well for TiO2 (GSD = 1.3), but not for MWCNT and WF as evidenced by the large GSD values of 1.8 and 1.5, respectively. For overall characterization, results from SMPS (scanning voltage mode) exhibited particle-dependent discrepancies in the size distribution and total number concentration compared to those from microscopic analysis. Further investigation showed that use of a single-stage impactor at the SMPS inlet could distort the size distribution and underestimate the concentration as shown by the SMPS, whereas the presence of vapor molecules or atom clusters in

  16. Processing of radioactive waste by the use of low energy ({le} 100 MeV) charged particle accelerators. Optimization problems

    SciTech Connect

    Mushnikov, V.N.; Ozhigov, L.S.; Khizhnyak, N.A.

    1993-12-31

    The radiation processing of long-lived radiotoxic elements is based on transmutation reactions under the action of various particles and energies. Among the different particle sources the most promising is the proton accelerator. The present work studied the process of radiation deactivation in the stationary proton flux as functions of their flux density and energy. The Bateman-Robinson differential equations were solved.

  17. Airborne and ground-based measurements of the trace gases and particles emitted from prescribed fires in the United States

    SciTech Connect

    Burling, Ian; Yokelson, Robert J.; Akagi, Sheryl; Urbanski, Shawn; Wold, Cyle E.; Griffith, David WT; Johnson, Timothy J.; Reardon, James; Weise, David

    2011-12-07

    We measured the emission factors for 19 trace gas species and particulate matter (PM2.5) from 14 prescribed fires in chaparral and oak savanna in the southwestern US, as well as pine forest understory in the southeastern US and Sierra Nevada mountains of California. These are likely the most extensive emission factor field measurements for temperate biomass burning to date and the only published emission factors for temperate oak savanna fuels. This study helps close the gap in emissions data available for temperate zone fires relative to tropical biomass burning. We present the first field measurements of the biomass burning emissions of glycolaldehyde, a possible precursor for aqueous phase secondary organic aerosol formation. We also measured the emissions of phenol, another aqueous phase secondary organic aerosol precursor. Our data confirm previous suggestions that urban deposition can impact the NOx emission factors and thus subsequent plume chemistry. For two fires, we measured the emissions in the convective smoke plume from our airborne platform at the same time the unlofted residual smoldering combustion emissions were measured with our ground-based platform after the flame front passed through. The smoke from residual smoldering combustion was characterized by emission factors for hydrocarbon and oxygenated organic species that were up to ten times higher than in the lofted plume, including significant 1,3-butadiene and isoprene concentrations which were not observed in the lofted plume. This should be considered in modeling the air quality impacts of smoke that disperses at ground level, and we show that the normally-ignored unlofted emissions can also significantly impact estimates of total emissions. Preliminary evidence of large emissions of monoterpenes was seen in the residual smoldering spectra, but we have not yet quantified these emissions. These data should lead to an improved capacity to model the impacts of biomass burning in similar

  18. Exposure to Airborne Particles and Volatile Organic Compounds from Polyurethane Molding, Spray Painting, Lacquering, and Gluing in a Workshop

    PubMed Central

    Mølgaard, Bjarke; Viitanen, Anna-Kaisa; Kangas, Anneli; Huhtiniemi, Marika; Larsen, Søren Thor; Vanhala, Esa; Hussein, Tareq; Boor, Brandon E.; Hämeri, Kaarle; Koivisto, Antti Joonas

    2015-01-01

    Due to the health risk related to occupational air pollution exposure, we assessed concentrations and identified sources of particles and volatile organic compounds (VOCs) in a handcraft workshop producing fishing lures. The work processes in the site included polyurethane molding, spray painting, lacquering, and gluing. We measured total VOC (TVOC) concentrations and particle size distributions at three locations representing the various phases of the manufacturing and assembly process. The mean working-hour TVOC concentrations in three locations studied were 41, 37, and 24 ppm according to photo-ionization detector measurements. The mean working-hour particle number concentration varied between locations from 3000 to 36,000 cm−3. Analysis of temporal and spatial variations of TVOC concentrations revealed that there were at least four substantial VOC sources: spray gluing, mold-release agent spraying, continuous evaporation from various lacquer and paint containers, and either spray painting or lacquering (probably both). The mold-release agent spray was indirectly also a major source of ultrafine particles. The workers’ exposure can be reduced by improving the local exhaust ventilation at the known sources and by increasing the ventilation rate in the area with the continuous source. PMID:25849539

  19. TRENDS OF POLYCYCLIC AROMATIC HYDROCARBON LEVELS AND MUTAGENICITY IN SANTIAGO'S INHALABLE AIRBORNE PARTICLES IN THE PERIOD 1992-1996.

    EPA Science Inventory

    Abstract

    Trends of polycyclic aromatic hydrocarbons (PAHs) for 1992-1996 (cold season) and their mutagenic activity were investigated in organic extracts from the Santiago. Chile. inhalable particles (PM10). The highest PAH concentrations were observed in 1992 and decline...

  20. Decabromodiphenyl ether (deca-BDE) commercial mixture components, and other PBDEs, in airborne particles at a UK site.

    PubMed

    Wilford, Bryony H; Thomas, Gareth O; Jones, Kevin C; Davison, Brian; Hurst, Debra K

    2008-04-01

    The occurrence of the major components of the decabromodiphenyl ether (deca-BDE) flame retardant and other PBDEs was investigated in daily air particulate samples from 17th April to 20th May 2004 at a semi-rural site in north-west England. BDE-209 was found at between <0.49 and 100 pg m(-3) (median 13 pg m(-3)), and other higher-brominated PBDE congeners were also found, particularly the nona-BDEs (e.g. BDE-207: <0.042-79 pg m(-3), median 2.5 pg m(-3)). Deca- and nona-BDEs dominated the median particulate sample congener profile: 60% BDE-209, 16% BDE-207, 6% BDE-208 and 4% BDE-206. Nona-BDEs were greatly enriched, relative to BDE-209, compared to the deca-BDE commercial mixture, which may suggest degradation of BDE-209 between source and sampling site, or release from older deca-BDE commercial mixtures, which may have contained higher proportions of nona-BDEs. The highest PBDE concentrations occurred when air-masses passed over urban and industrial areas to the SSW-SW, though small local influences may also be seen. PBDE concentrations appear to have been influenced mainly by particle levels: 1-3 microm diameter particles for BDE-153, and 3-10 microm particles for BDEs with 7-10 Br atoms. BDE-153 may either be released from combustion sources, or re-condense onto small particles after emission, whereas BDE-209 and nona-BDEs appear to be associated with larger dust particles from industrial or domestic sources.

  1. SIZE DISTRIBUTION AND RATE OF PRODUCTION OF AIRBORNE PARTICULATE MATTER GENERATED DURING METAL CUTTING

    SciTech Connect

    M.A. Ebadian, Ph.D.; S.K. Dua, Ph.D., C.H.P.; Hillol Guha, Ph.D.

    2001-01-01

    During deactivation and decommissioning activities, thermal cutting tools, such as plasma torch, laser, and gasoline torch, are used to cut metals. These activities generate fumes, smoke and particulates. These airborne species of matter, called aerosols, may be inhaled if suitable respiratory protection is not used. Inhalation of the airborne metallic aerosols has been reported to cause ill health effects, such as acute respiratory syndrome and chromosome damage in lymphocytes. In the nuclear industry, metals may be contaminated with radioactive materials. Cutting these metals, as in size reduction of gloveboxes and tanks, produces high concentrations of airborne transuranic particles. Particles of the respirable size range (size < 10 {micro}m) deposit in various compartments of the respiratory tract, the fraction and the site in the respiratory tract depending on the size of the particles. The dose delivered to the respiratory tract depends on the size distribution of the airborne particulates (aerosols) and their concentration and radioactivity/toxicity. The concentration of airborne particulate matter in an environment is dependent upon the rate of their production and the ventilation rate. Thus, measuring aerosol size distribution and generation rate is important for (1) the assessment of inhalation exposures of workers, (2) the selection of respiratory protection equipment, and (3) the design of appropriate filtration systems. Size distribution of the aerosols generated during cutting of different metals by plasma torch was measured. Cutting rates of different metals, rate of generation of respirable mass, as well as the fraction of the released kerf that become respirable were determined. This report presents results of these studies. Measurements of the particles generated during cutting of metal plates with a plasma arc torch revealed the presence of particles with mass median aerodynamic diameters of particles close to 0.2 {micro}m, arising from

  2. Characterization of Size-Fractionated Airborne Particles Inside an Electronic Waste Recycling Facility and Acute Toxicity Testing in Mice.

    PubMed

    Kim, Yong Ho; Wyrzykowska-Ceradini, Barbara; Touati, Abderrahmane; Krantz, Q Todd; Dye, Janice A; Linak, William P; Gullett, Brian; Gilmour, M Ian

    2015-10-06

    Disposal of electronic waste (e-waste) in landfills, incinerators, or at rudimentary recycling sites can lead to the release of toxic chemicals into the environment and increased health risks. Developing e-waste recycling technologies at commercial facilities can reduce the release of toxic chemicals and efficiently recover valuable materials. While these e-waste operations represent a vast improvement over previous approaches, little is known about environmental releases, workplace exposures, and potential health impacts. In this study, airborne particulate matter (PM) was measured at various locations within a modern U.S.-based e-waste recycling facility that utilized mechanical processing. In addition, composite size fractionated PM (coarse, fine and ultrafine) samples were collected, extracted, chemically analyzed, and given by oropharyngeal aspiration to mice or cultured with lung slices for lung toxicity tests. Indoor total PM concentrations measured during the study ranged from 220 to 1200 μg/m(3). In general, the coarse PM (2.5-10 μm) was 3-4 times more abundant than fine/ultrafine PM (<2.5 μm). The coarse PM contained higher levels of Ni, Pb, and Zn (up to 6.8 times) compared to the fine (0.1-2.5 μm) and ultrafine (<0.1 μm) PM. Compared to coarse PM measurements from a regional near-roadway study, Pb and Ni were enriched 170 and 20 times, respectively, in the indoor PM, with other significant enrichments (>10 times) observed for Zn and Sb, modest enrichments (>5 times) for Cu and Sr, and minor enrichments (>2 times) for Cr, Cd, Mn, Ca, Fe, and Ba. Negligible enrichment (<2 times) or depletion (<1 time) were observed for Al, Mg, Ti, Si, and V. The coarse PM fraction elicited significant pro-inflammatory responses in the mouse lung at 24 h postexposure compared to the fine and ultrafine PM, and similar toxicity outcomes were observed in the lung slice model. We conclude that exposure to coarse PM from the facility caused substantial inflammation in the

  3. Size fractionation in mercury-bearing airborne particles (HgPM 10) at Almadén, Spain: Implications for inhalation hazards around old mines

    NASA Astrophysics Data System (ADS)

    Moreno, Teresa; Higueras, Pablo; Jones, Tim; McDonald, Iain; Gibbons, Wes

    Almadén has a >2000y mining history and an unprecedented legacy of mercury contamination. Resuspended airborne particles were extracted from mine waste (Las Cuevas), retort site soil (Almadenejos), and urban car park dust (Almadén), separated into fine (PM 10) and coarse (PM >10 μm ) fractions, analysed for mercury using ICP-MS, and individual HgPM characterised using SEM. Cold extractable mercury concentrations in PM 10 range from 100 to 150 μg g -1 (car parks), to nearly 6000 μg g -1 (mine waste), reaching a world record of 95,000 μg g -1 above the abandoned retort at Almadenejos where ultrafine HgPM have pervaded the brickwork and soil and entered the food chain: edible wild asparagus stem material from here contains 35-65 μg g -1 Hg, and pig hair from animals living, inhaling and ingesting HgPM 10 at the site yielded 8-10 μg g -1. The PM 10 fraction (dusts easily wind transported and deeply inhaled) contains much more mercury than the coarser fraction. The contribution of HgPM 10 to ecosystem contamination and potential human health effects around old mercury mines has been underestimated.

  4. Organophosphorus flame retardants and plasticizers in airborne particles over the Northern Pacific and Indian Ocean toward the Polar Regions: evidence for global occurrence.

    PubMed

    Möller, Axel; Sturm, Renate; Xie, Zhiyong; Cai, Minghong; He, Jianfeng; Ebinghaus, Ralf

    2012-03-20

    Organophosphorus compounds (OPs) being applied as flame retardants and plasticizers were investigated in airborne particles over the Pacific, Indian, Arctic, and Southern Ocean. Samples taken during two polar expeditions in 2010/11, one from East Asia to the high Arctic (CHINARE 4) and another from East Asia toward the Indian Ocean to the Antarctic (CHINARE 27), were analyzed for three halogenated OPs (tris(2-chloroethyl) phosphate (TCEP), tris(2-chloroisopropyl) phosphate (TCPP) and tris(1,3-dichloro-2-isopropyl) phosphate (TDCP)), four alkylated OPs (tri-n-butyl phosphate (TnBP), tri-iso-butyl phosphate (TiBP), tris(2-butoxyethyl)phosphate (TBEP), and tris(2-ethylhexyl) phosphate (TEHP)), and triphenyl phosphate (TPhP). The sum of the eight investigated OPs ranged from 230 to 2900 pg m(-3) and from 120 to 1700 pg m(-3) during CHINARE 4 and CHINARE 27, respectively. TCEP and TCPP were the predominating compounds, both over the Asian seas as well as in the polar regions, with concentrations from 19 to 2000 pg m(-3) and 22 to 620 pg m(-3), respectively. Elevated concentrations were observed in proximity to the Asian continent enhanced by continental air masses. They decreased sharply toward the open oceans where they remained relatively stable. This paper shows the first occurrence of OPs over the global oceans proving that they undergo long-range atmospheric transport over the global oceans toward the Arctic and Antarctica.

  5. Application of Salmonella strains with altered nitroreductase and O-acetyltransferase activities to the evaluation of the mutagenicity of airborne particles.

    PubMed

    Adamiak, W; Jadczyk, P; Kucharczyk, J

    1999-01-01

    The Ames test was applied to evaluation of the mutagenicity of month's samples of airborne particles from the center of Wrocław (SW Poland) collected in August and December 1997. The strains used for the study were TA 98, TA 100 and their derivatives: TA 98 NR, YG 1021, YG 1024, YG 1026, YG 1029, YG 1041, YG 1042. Both studied samples were mutagenic for almost all tested strains, with the exception of the August sample which did not influence the strain TA 100 without the metabolic activation with the S9 fraction. The December sample exhibited higher genotoxic activity than the August sample. Mutagenicity ratios of the strains with reduced nitroreductase and O-acetyltransferase activities were higher, and of the strain without the nitroreductase--lower than those of the parent strains. This indicates that nitro and amino derivatives of PAHs are responsible for the significant proportion of total mutagenicity of the studied samples of particulates. Metabolic activation with the S9 fraction caused the increase of the mutagenic activity of the samples, which indicates the presence of promutagens. The GC-MS analysis revealed the presence of known indirect mutagens from the PAHs group.

  6. Experimental and numerical study of gas-to-particle conversion in an emission plume from mining and metallurgical industry based on airborne sounding in a polar atmosphere

    NASA Astrophysics Data System (ADS)

    Simonenkov, Denis V.; Raputa, Vladimir F.; Yaroslavtseva, Tatyana V.; Belan, Boris D.

    2016-11-01

    The results of an airborne survey of plumes from the Norilsk Mining and Metallurgical Plant by an Optik-É AN-30 aircraft laboratory on November 10, 2002 are discussed. Most pollutants are blown out of the city in the gas phase in the form of acidic oxides (mainly sulfur). Mapping of the substances is performed along the main trajectory of air mass transport at a distance of 20-140 km from the city. Horizontal flights were performed at 400, 600, 800, and 1200 m above sea level at equidistant traverses (from 3 to 6 at each height) normally to the main flow direction. Most pollution was concentrated above the 400-m level. An active gas-to-particle conversion was observed at a distance of 60-100 km from the emission source. In the plume areas distant from the source there was a sulfate anion increase from 4% to 51% in aerosol composition weight and a calcium decrease from 64% to 9%. Under the conditions of low humidity in the polar atmosphere in winter, SO2 is apparently removed from the air mainly due to dry heterogeneous condensation with calcium oxide as the main counteragent of industrial origin. The concentrations of these active pollutants in the plume are well approximated by a two-parameter transformation model.

  7. Airborne urban particles (Milan winter-PM2.5) cause mitotic arrest and cell death: Effects on DNA, mitochondria, AhR binding and spindle organization.

    PubMed

    Gualtieri, Maurizio; Ovrevik, Johan; Mollerup, Steen; Asare, Nana; Longhin, Eleonora; Dahlman, Hans-Jørgen; Camatini, Marina; Holme, Jørn A

    2011-08-01

    Airborne particulate matter (PM) is considered to be an important contributor to lung diseases. In the present study we report that Milan winter-PM2.5 inhibited proliferation in human bronchial epithelial cells (BEAS-2B) by inducing mitotic arrest. The cell cycle arrest was followed by an increase in mitotic-apoptotic cells, mitotic slippage and finally an increase in "classical" apoptotic cells. Exposure to winter-PM10 induced only a slight effect which may be due to the presence of PM2.5 in this fraction while pure combustion particles failed to disturb mitosis. Fewer cells expressing the mitosis marker phospho-histone H3 compared to cells with condensed chromosomes, suggest that PM2.5 induced premature mitosis. PM2.5 was internalized into the cells and often localized in laminar organelles, although particles without apparent plasma membrane covering were also seen. In PM-containing cells mitochondria and lysosomes were often damaged, and in mitotic cells fragmented chromosomes often appeared. PM2.5 induced DNA strands breaks and triggered a DNA-damage response characterized by increased phosphorylation of ATM, Chk2 and H2AX; as well as induced a marked increase in expression of the aryl hydrocarbon receptor (AhR)-regulated genes, CYP1A1, CYP1B1 and AhRR. Furthermore, some disturbance of the organization of microtubules was indicated. It is hypothesized that the induced mitotic arrest and following cell death was due to a premature chromosome condensation caused by a combination of DNA, mitochondrial and spindle damage.

  8. Airborne particulate matter in spacecraft

    NASA Technical Reports Server (NTRS)

    1988-01-01

    Acceptability limits and sampling and monitoring strategies for airborne particles in spacecraft were considered. Based on instances of eye and respiratory tract irritation reported by Shuttle flight crews, the following acceptability limits for airborne particles were recommended: for flights of 1 week or less duration (1 mg/cu m for particles less than 10 microns in aerodynamic diameter (AD) plus 1 mg/cu m for particles 10 to 100 microns in AD); and for flights greater than 1 week and up to 6 months in duration (0.2 mg/cu m for particles less than 10 microns in AD plus 0.2 mg/cu m for particles 10 to 100 microns in AD. These numerical limits were recommended to aid in spacecraft atmosphere design which should aim at particulate levels that are a low as reasonably achievable. Sampling of spacecraft atmospheres for particles should include size-fractionated samples of 0 to 10, 10 to 100, and greater than 100 micron particles for mass concentration measurement and elementary chemical analysis by nondestructive analysis techniques. Morphological and chemical analyses of single particles should also be made to aid in identifying airborne particulate sources. Air cleaning systems based on inertial collection principles and fine particle collection devices based on electrostatic precipitation and filtration should be considered for incorporation into spacecraft air circulation systems. It was also recommended that research be carried out in space in the areas of health effects and particle characterization.

  9. [Influence of nuclear reactor accident at Chernobyl' on the environmental radioactivity in Toyama].

    PubMed

    Morita, M; Shoji, M; Honda, T; Sakanoue, M

    1987-06-01

    The environmental radioactivity caused by the reactor accident at Chernobyl' was investigated from May 7 to May 31 of 1986 in Toyama. Measurement of radioactivities in airborne particles, rain water, drinking water, milk, and mugwort are carried out by gamma-ray spectrometry (pure Ge detector; ORTEC GMX-23195). Ten different nuclides (103Ru, 106Ru, 131I, 132Te-I, 134Cs, 136Cs, 137Cs, 140Ba-La) are identified from samples of airborne particles. In the air samples, a maximum radioactivity concentration of each nuclide is observed on 13th May 1986. The time of the reactor shut-down and the flux of thermal neutron at the reactor were calculated from 131I/132I and 137Cs/134Cs ratio. The exposure dose in Toyama by this accident is given as follows: internal exposure; [thyroid] adult-59 microSv, child-140 microSv, baby-130 microSv, [total body] adult-0.2 microSv, child, baby-0.4 microSv, external exposure; 7 microSv, effective dose equivalent; adult-9 microSv, child-12 Sv, baby-11 microSv.

  10. Fourth Airborne Geoscience Workshop

    NASA Technical Reports Server (NTRS)

    1991-01-01

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

  11. Measurements of radioactive contaminants in semiconductor materials

    NASA Astrophysics Data System (ADS)

    Gordon, Michael S.; Rodbell, Kenneth P.; Murray, Conal E.; McNally, Brendan D.

    2016-12-01

    The emission of alpha particles from materials used to manufacture semiconductors can contribute substantially to the single-event upset rate. The alpha particles originate from contamination in the materials, or from radioactive isotopes, themselves. In this review paper, we discuss the sources of the radioactivity and the measurement methods to detect the emitted particles.

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

    PubMed

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

    2000-03-01

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

  13. Airborne Imagery

    NASA Technical Reports Server (NTRS)

    1983-01-01

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

  14. Hypersensitivity of prediabetic JCR:LA-cp rats to fine airborne combustion particle-induced direct and noradrenergic-mediated vascular contraction.

    PubMed

    Proctor, Spencer D; Dreher, Kevin L; Kelly, Sandra E; Russell, James C

    2006-04-01

    Particulate matter with mean aerodynamic diameter < or =2.5 microm (PM(2.5)), from diesel exhaust, coal or residual oil burning, and from industrial plants, is a significant component of airborne pollution. Type 2 diabetes is associated with enhanced risk of adverse cardiovascular events following exposure to PM(2.5). Particle properties, sources, and pathophysiological mechanisms responsible are unknown. We studied effects of residual oil fly ash (ROFA) from a large U.S. powerplant on vascular function in a prediabetic, hyperinsulinemic model, the JCR:LA-cp rat. Residual oil fly ash leachate (ROFA-L) was studied using aortic rings from young-adult, obese, insulin-resistant rats and lean normal rats in vitro. Contractile response to phenylephrine and relaxant response to acetylcholine were determined in the presence and absence of L-NAME (N(G)-nitro-L-arginine methyl ester). In a separate series of studies, the direct contractile effects of ROFA-L on repeated exposure were determined. ROFA-L (12.5 microg ml(-1)) increased phenylephrine-mediated contraction in obese (p < 0.05), but not in lean rat aortae, with the effect being exacerbated by L-NAME, and it reduced acetylcholine-mediated relaxation of both obese and lean aortae (p < 0.0001). Initial exposure of aortae to ROFA-L caused a small contractile response (<0.05 g), which was markedly greater on second exposure in the obese (approximately 0.6 g, p < 0.0001) aortae but marginal in lean (approximately 0.1 g) aortae. Our data demonstrate that bioavailable constituents of oil combustion particles enhance noradrenergic-mediated vascular contraction, impair endothelium-mediated relaxation, and induce direct vasocontraction in prediabetic rats. These observations provide the first direct evidence of the causal properties of PM(2.5) and identify the pathophysiological role of the early prediabetic state in susceptibility to environmentally induced cardiovascular disease. These are important implications for public

  15. SOURCES OF HUMAN EXPOSURE TO AIRBORNE PAH

    EPA Science Inventory

    Personal exposures to airborne particulate polycyclic aromatic hydrocarbons (PAHs) were studied in several populations in the US, Japan, and Czech Republic. Personal exposure monitors, developed for human exposure biomonitoring studies were used to collect fine particles (<_ 1....

  16. Radioactive Wastes.

    PubMed

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes.

  17. Radioactive Wastes.

    PubMed

    Choudri, B S; Baawain, Mahad

    2016-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2015. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes.

  18. Airborne Gamma-Spectrometry in Switzerland

    NASA Astrophysics Data System (ADS)

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-01

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

  19. Airborne Gamma-Spectrometry in Switzerland

    SciTech Connect

    Butterweck, Gernot; Bucher, Benno; Rybach, Ladislaus

    2008-08-07

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

  20. Radioactivity Calculations

    ERIC Educational Resources Information Center

    Onega, Ronald J.

    1969-01-01

    Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

  1. Concentrating Radioactivity

    ERIC Educational Resources Information Center

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  2. Simulated Radioactivity

    ERIC Educational Resources Information Center

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  3. 10 CFR 835.209 - Concentrations of radioactive material in air.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Concentrations of radioactive material in air. 835.209... External Exposure § 835.209 Concentrations of radioactive material in air. (a) The derived air... exposures to airborne radioactive material. (b) The estimation of internal dose shall be based on...

  4. Monitoring airborne alpha-emitter contamination

    SciTech Connect

    Kerr, P.L.; Koster, J.E.; Conaway, J.G.; Bounds, J.A.; Whitley, C.W.; Steadman, P.A.

    1998-02-01

    Facilities that may produce airborne alpha emitter contamination require a continuous air monitoring (CAM) system. However, these traditional CAMs have difficulty in environments with large quantities of non-radioactive particulates such as dust and salt. Los Alamos has developed an airborne plutonium sensor (APS) for the REBOUND experiment at the Nevada Test Site which detects alpha contamination directly in the air, and so is less vulnerable to the problems associated with counting activity on a filter. In addition, radon compensation is built into the detector by the use of two measurement chambers.

  5. In-depth compositional analysis of water-soluble and -insoluble organic substances in fine (PM2.5) airborne particles using ultra-high-resolution 15T FT-ICR MS and GC×GC-TOFMS.

    PubMed

    Choi, Jung Hoon; Ryu, Jijeong; Jeon, Sodam; Seo, Jungju; Yang, Yung-Hun; Pack, Seung Pil; Choung, Sungwook; Jang, Kyoung-Soon

    2017-03-05

    Airborne particulate matter consisting of ionic species, salts, heavy metals and carbonaceous material is one of the most serious environmental pollutants owing to its impacts on the environment and human health. Although elemental and organic carbon compounds are known to be major components of aerosols, information on the elemental composition of particulate matter remains limited because of the broad range of compounds involved and the limits of analytical instruments. In this study, we investigated water-soluble and -insoluble organic compounds in fine (PM2.5) airborne particles collected during winter in Korea to better understand the elemental compositions and distributions of these compounds. To collect ultra-high-resolution mass profiles, we analyzed water-soluble and -insoluble organic compounds, extracted with water and dichloromethane, respectively, using an ultra-high-resolution 15 T Fourier transform ion cyclotron resonance (15T FT-ICR) mass spectrometer in positive ion mode (via both electrospray ionization [ESI] and atmospheric pressure photoionization [APPI] for water-extracts and via APPI for dichloromethane-extracts). In conjunction with the FT-ICR mass spectrometry (MS) data, subsequent two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) data were used to identify potentially hazardous organic components, such as polycyclic aromatic hydrocarbons. This analysis provided information on the sources of ambient particles collected during winter season and partial evidence of contributions to the acidity of organic content in PM2.5 particles. The compositional and structural features of water-soluble and -insoluble organic compounds from PM2.5 particles are important for understanding the potential impacts of aerosol-carried organic substances on human health and global ecosystems in future toxicological studies.

  6. RADIOACTIVE BATTERY

    DOEpatents

    Birden, J.H.; Jordan, K.C.

    1959-11-17

    A radioactive battery which includes a capsule containing the active material and a thermopile associated therewith is presented. The capsule is both a shield to stop the radiations and thereby make the battery safe to use, and an energy conventer. The intense radioactive decay taking place inside is converted to useful heat at the capsule surface. The heat is conducted to the hot thermojunctions of a thermopile. The cold junctions of the thermopile are thermally insulated from the heat source, so that a temperature difference occurs between the hot and cold junctions, causing an electrical current of a constant magnitude to flow.

  7. Radioactive Waste.

    ERIC Educational Resources Information Center

    Blaylock, B. G.

    1978-01-01

    Presents a literature review of radioactive waste disposal, covering publications of 1976-77. Some of the studies included are: (1) high-level and long-lived wastes, and (2) release and burial of low-level wastes. A list of 42 references is also presented. (HM)

  8. A study of production of radioactive environmental reference materials used for proficiency testing program in Taiwan.

    PubMed

    Peng, En-Chi; Wang, Jeng-Jong

    2013-11-01

    To realise radioactive environmental reference materials in Taiwan, seven environmental materials of soil, water, vegetation, meat, airborne particles (filter paper), milk and mushroom samples that are frequently encountered were used to establish the preparation of the reference materials. These seven environmental materials were collected, checked for freedom from radioactivity and prepared according to their properties. The preparation was carried out by using activity about 10-100 times that of the minimum detectable activity (MDA) in routine measurements in the radioactive standard used to spike the inactive material and this standard is traceable to national ionising radioactivity standards (TAF, 2004). To demonstrate sample traceability to the added standard, each sample was carefully measured and its uncertainty evaluated. Based on the recommendations of ISO Guide 35 for evaluation of reference materials and with the above assessment and verification procedures, the uncertainties (k=1) of the spike activity used in making reference materials were: (60)Co≤4.6%, (134)Cs≤4.7%, (137)Cs≤5.0%, total β≤0.6% and (3)H≤1.3%.

  9. THE BIMODAL DISTRIBUTION: DEVELOPMENT OF THE CONCEPT OF FINE AND COARSE PARTICLES AS SEPARATE AND DISTINCT COMPONENTS OF AIRBORNE PARTICULATE MATTER

    EPA Science Inventory

    In the early 1970s, it was understood that combustion particles were formed mostly in sizes below 1 um diameter, and windblown dust was suspended in sizes mostly above 1 um diameter. However, particle size distribution was thought of as a single mode. Particles were thought to f...

  10. Radioactive ion detector

    DOEpatents

    Bower, K.E.; Weeks, D.R.

    1997-08-12

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity. 2 figs.

  11. Radioactive ion detector

    DOEpatents

    Bower, Kenneth E.; Weeks, Donald R.

    1997-01-01

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity.

  12. Influence of radioactivity on surface interaction forces.

    PubMed

    Walker, M E; McFarlane, J; Glasgow, D C; Chung, E; Taboada-Serrano, P; Yiacoumi, S; Tsouris, C

    2010-10-15

    Although some differences have been observed, the transport behavior of radioactive aerosol particles has often been assumed to be analogous to the behavior of nonradioactive aerosols in dispersion models. However, radioactive particles can become electrostatically charged as a result of the decay process. Theories have been proposed to describe this self-charging phenomenon, which may have a significant effect on how these particles interact with one another and with charged surfaces in the environment. In this study, atomic force microscopy (AFM) was employed to quantify surface forces between a particle and a planar surface and to compare measurements with and without the involvement of radioactivity. The main objective of this work is to assess directly the effects of radioactivity on the surface interactions of radioactive aerosols via the measurement of the adhesion force. The adhesion force between a silicon nitride AFM tip and an activated gold substrate was measured so that any possible effects due to radioactivity could be observed. The adhesion force between the tip and the gold surface increased significantly when the gold substrate (25 mm(2) surface area) was activated to a level of approximately 0.6 mCi. The results of this investigation will prompt further work into the effects of radioactivity in particle-surface interactions.

  13. Airborne in-situ investigations of the Eyjafjallajökull volcanic ash plume on Iceland and over north-western Germany with light aircrafts and optical particle counters

    NASA Astrophysics Data System (ADS)

    Weber, K.; Eliasson, J.; Vogel, A.; Fischer, C.; Pohl, T.; van Haren, G.; Meier, M.; Grobéty, B.; Dahmann, D.

    2012-03-01

    During the time period of the eruption of the Icelandic volcano Eyjafjallajökull in April/May 2010 the Duesseldorf University of Applied Sciences has performed 14 research flights in situations with and without the volcanic ash plume over Germany. In parallel to the research flights in Germany three measurement flights have been performed by the University of Iceland in May 2010 over the western part of Iceland. During two of these flights the outskirts of the eruption plume were entered directly, delivering most direct measurements within the eruption plume during this eruptive event. For all the measurement flights reported here, light durable piston-motor driven aircrafts were used, which were equipped with optical particle counters for in-situ measurements. Real-time monitoring of the particle concentrations was possible during the flights. As different types of optical particle counters have been used in Iceland and Germany, the optical particle counters have been re-calibrated after the flights to the same standard using gravimetric reference methods and original Eyjafjallajökull volcanic ash samples. In-situ measurement results with high spatial resolution, directly from the eruption plume in Iceland as well as from the dispersed and several days old plume over Germany, are therefore presented here for the first time. They are normalized to the same ash concentration calibration standard. Moreover, airborne particles could be sampled directly out of the eruption plume in Iceland as well as during the flights over Germany. During the research flights over Iceland from 9 May 2011 to 11 May 2011 the ash emitted from the vent of the volcano turned out to be concentrated in a narrow well-defined plume of about 10 km width at a distance of 45-60 km away from the vent. Outside this plume the airborne ash concentrations could be proved to be below 50 μg m -3 over western Iceland. However, by entering the outskirts of the plume directly the research aircraft could

  14. Quality Assurance Program Plan for radionuclide airborne emissions monitoring

    SciTech Connect

    Vance, L.M.

    1993-07-01

    This Quality Assurance Program Plan (QAPP) describes the quality assurance requirements and responsibilities for radioactive airborne emissions measurements activities from regulated stacks are controlled at the Hanford Site. Detailed monitoring requirements apply to stacks exceeding 1% of the standard of 10 mrem annual effective dose equivalent to the maximally exposed individual from operations of the Hanford Site.

  15. Airborne Single Particle Mass Spectrometers (SPLAT II & miniSPLAT) and New Software for Data Visualization and Analysis in a Geo-Spatial Context

    SciTech Connect

    Zelenyuk, Alla; Imre, D.; Wilson, Jacqueline M.; Zhang, Zhiyuan; Wang, Jun; Mueller, Klaus

    2015-02-01

    Understanding the effect of aerosols on climate requires knowledge of the size and chemical composition of individual aerosol particles - two fundamental properties that determine an aerosol’s optical properties and ability to serve as cloud condensation or ice nuclei. Here we present miniSPLAT, our new aircraft compatible single particle mass spectrometer, that measures in-situ and in real-time size and chemical composition of individual aerosol particles with extremely high sensitivity, temporal resolution, and sizing precision on the order of a monolayer. miniSPLAT operates in dual data acquisition mode to measure, in addition to single particle size and composition, particle number concentrations, size distributions, density, and asphericity with high temporal resolution. When compared to our previous instrument, SPLAT II, miniSPLAT has been significantly reduced in size, weight, and power consumption without loss in performance. We also present ND-Scope, our newly developed interactive visual analytics software package. ND-Scope is designed to explore and visualize the vast amount of complex, multidimensional data acquired by our single particle mass spectrometers, along with other aerosol and cloud characterization instruments on-board aircraft. We demonstrate that ND-Scope makes it possible to visualize the relationships between different observables and to view the data in a geo-spatial context, using the interactive and fully coupled Google Earth and Parallel Coordinates displays. Here we illustrate the utility of ND-Scope to visualize the spatial distribution of atmospheric particles of different compositions, and explore the relationship between individual particle composition and their activity as cloud condensation nuclei.

  16. Airborne Single Particle Mass Spectrometers (SPLAT II & miniSPLAT) and New Software for Data Visualization and Analysis in a Geo-Spatial Context

    NASA Astrophysics Data System (ADS)

    Zelenyuk, Alla; Imre, Dan; Wilson, Jacqueline; Zhang, Zhiyuan; Wang, Jun; Mueller, Klaus

    2015-02-01

    Understanding the effect of aerosols on climate requires knowledge of the size and chemical composition of individual aerosol particles—two fundamental properties that determine an aerosol's optical properties and ability to serve as cloud condensation or ice nuclei. Here we present our aircraft-compatible single particle mass spectrometers, SPLAT II and its new, miniaturized version, miniSPLAT that measure in-situ and in real-time the size and chemical composition of individual aerosol particles with extremely high sensitivity, temporal resolution, and sizing precision on the order of a monolayer. Although miniSPLAT's size, weight, and power consumption are significantly smaller, its performance is on par with SPLAT II. Both instruments operate in dual data acquisition mode to measure, in addition to single particle size and composition, particle number concentrations, size distributions, density, and asphericity with high temporal resolution. We also present ND-Scope, our newly developed interactive visual analytics software package. ND-Scope is designed to explore and visualize the vast amount of complex, multidimensional data acquired by our single particle mass spectrometers, along with other aerosol and cloud characterization instruments on-board aircraft. We demonstrate that ND-Scope makes it possible to visualize the relationships between different observables and to view the data in a geo-spatial context, using the interactive and fully coupled Google Earth and Parallel Coordinates displays. Here we illustrate the utility of ND-Scope to visualize the spatial distribution of atmospheric particles of different compositions, and explore the relationship between individual particle compositions and their activity as cloud condensation nuclei.

  17. Biomass burning layers measured with an airborne Single Particle Soot Photometer (SP2) during the Deep Convective Clouds and Chemistry (DC3) experiment

    NASA Astrophysics Data System (ADS)

    Heimerl, K.; Weinzierl, B.; Minikin, A.; Sauer, D. N.; Fütterer, D.; Lichtenstern, M.; Schlager, H.; Schwarz, J. P.; Markovic, M. Z.; Perring, A. E.; Fahey, D. W.; Huntrieser, H.

    2013-12-01

    The 2012 wildfire season in the U.S. was one of the worst in the past decade. Coinciding with the period of intense wildfires in the western U.S., the Deep Convective Clouds and Chemistry (DC3) experiment took place in the central U.S. in May and June of 2012. Although the main goal of this experiment was to characterize chemical processes in and around thunderstorms, biomass burning plumes from wildfires were also measured during almost every flight. Measurements were performed with three different research aircraft (NCAR GV, NASA DC8 and DLR Falcon 20E), accompanied by ground based measurements with radars and radiosondes, and measurements of meteorological parameters and lightning. The instrumentation aboard the DLR Falcon included measurements of the trace gases NO, CO, O3, CO2, CH4, SO2, volatile organic compounds, and a variety of aerosol microphysical parameters. To cover a wide range of aerosol particle sizes, the DLR Falcon payload included optical particle counters (UHSAS-A, FSSP-300, FSSP-100, PCASP-100X/SPP-200 and Sky-OPC 1.129), a multi-channel CPC system for measuring total and non-volatile particle concentrations and, for absorbing particles, a three-wavelength PSAP and a Single Particle Soot Photometer (SP2). We will focus on the latter in this presentation. The SP2 measures both the mass of refractory black carbon (rBC) particles as well as their optical size, providing information about the mixing state of particles in the biomass burning layers. Most biomass burning layers were found between 3 and 8 km altitude. We will discuss measurements of plumes originating from New Mexico wildfires (Little Bear wildfire on June 11th of 2012 and Whitewater-Baldy wildfire on May 29th and 30th of 2012). Peaks of the rBC mass concentration in the plumes were as high as 2μg/m3, the fraction of rBC particles with thick coatings was higher than what is usually found in the boundary layer. During the Falcon transfer flights from Germany to the U.S. and back

  18. BioAerosol Mass Spectrometry: Reagentless Detection of Individual Airborne Spores and Other Bioagent Particles Based on Laser Desorption/Ionization Mass Spectrometry

    SciTech Connect

    Steele, Paul Thomas

    2004-09-01

    Better devices are needed for the detection of aerosolized biological warfare agents. Advances in the ongoing development of one such device, the BioAerosol Mass Spectrometry (BAMS) system, are described here in detail. The system samples individual, micrometer-sized particles directly from the air and analyzes them in real-time without sample preparation or use of reagents. At the core of the BAMS system is a dual-polarity, single-particle mass spectrometer with a laser based desorption and ionization (DI) system. The mass spectra produced by early proof-of-concept instruments were highly variable and contained limited information to differentiate certain types of similar biological particles. The investigation of this variability and subsequent changes to the DI laser system are described. The modifications have reduced the observed variability and thereby increased the usable information content in the spectra. These improvements would have little value without software to analyze and identify the mass spectra. Important improvements have been made to the algorithms that initially processed and analyzed the data. Single particles can be identified with an impressive level of accuracy, but to obtain significant reductions in the overall false alarm rate of the BAMS instrument, alarm decisions must be made dynamically on the basis of multiple analyzed particles. A statistical model has been developed to make these decisions and the resulting performance of a hypothetical BAMS system is quantitatively predicted. The predictions indicate that a BAMS system, with reasonably attainable characteristics, can operate with a very low false alarm rate (orders of magnitude lower than some currently fielded biodetectors) while still being sensitive to small concentrations of biological particles in a large range of environments. Proof-of-concept instruments, incorporating some of the modifications described here, have already performed well in independent testing.

  19. Geophex Airborne Unmanned Survey System

    SciTech Connect

    Won, I.L.; Keiswetter, D.

    1995-12-31

    Ground-based surveys place personnel at risk due to the proximity of buried unexploded ordnance (UXO) items or by exposure to radioactive materials and hazardous chemicals. The purpose of this effort is to design, construct, and evaluate a portable, remotely-piloted, airborne, geophysical survey system. This non-intrusive system will provide stand-off capability to conduct surveys and detect buried objects, structures, and conditions of interest at hazardous locations. During a survey, the operators remain remote from, but within visual distance of, the site. The sensor system never contacts the Earth, but can be positioned near the ground so that weak geophysical anomalies can be detected. The Geophex Airborne Unmanned Survey System (GAUSS) is designed to detect and locate small-scale anomalies at hazardous sites using magnetic and electromagnetic survey techniques. The system consists of a remotely-piloted, radio-controlled, model helicopter (RCH) with flight computer, light-weight geophysical sensors, an electronic positioning system, a data telemetry system, and a computer base-station. The report describes GAUSS and its test results.

  20. Radioactive decay.

    PubMed

    Groch, M W

    1998-01-01

    When a parent radionuclide decays to its daughter radionuclide by means of alpha, beta, or isomeric transition, the decay follows an exponential form, which is characterized by the decay constant lambda. The decay constant represents the probability per unit time that a single radioatom will decay. The decay equation can be used to provide a useful expression for radionuclide decay, the half-life, the time when 50% of the radioatoms present will have decayed. Radiotracer half-life has direct implications in nuclear imaging, radiation therapy, and radiation safety because radionuclide half-life affects the ability to evaluate tracer kinetics and create appropriate nuclear images and also affects organ, tumor, and whole-body radiation dose. The number of radioatoms present in a sample is equal to the activity, defined as the number of transitions per unit time, divided by the decay constant; the mass of radioatoms present in a sample can be calculated to determine the specific activity (activity per unit mass). The dynamic relationship between the number of parent and daughter atoms present over time may lead to radioactive equilibrium, which takes two forms--secular and transient--and has direct relevance to generator-produced radionuclides.

  1. Molecular composition and size distribution of sugars, sugar-alcohols and carboxylic acids in airborne particles during a severe urban haze event caused by wheat straw burning

    NASA Astrophysics Data System (ADS)

    Wang, Gehui; Chen, Chunlei; Li, Jianjun; Zhou, Bianhong; Xie, Mingjie; Hu, Shuyuan; Kawamura, Kimitaka; Chen, Yan

    2011-05-01

    Molecular compositions and size distributions of water-soluble organic compounds (WSOC, i.e., sugars, sugar-alcohols and carboxylic acids) in particles from urban air of Nanjing, China during a severe haze event caused by field burning of wheat straw were characterized and compared with those in the summer and autumn non-haze periods. During the haze event levoglucosan (4030 ng m -3) was the most abundant compound among the measured WSOC, followed by succinic acid, malic acid, glycerol, arabitol and glucose, being different from those in the non-haze samples, in which sucrose or azelaic acid showed a second highest concentration, although levoglucosan was the highest. The measured WSOC in the haze event were 2-20 times more than those in the non-hazy days. Size distribution results showed that there was no significant change in the compound peaks in coarse mode (>2.1 μm) with respect to the haze and non-haze samples, but a large difference in the fine fraction (<2.1 μm) was found with a sharp increase during the hazy days mostly due to the increased emissions of wheat straw burning. Molecular compositions of organic compounds in the fresh smoke particles from wheat straw burning demonstrate that sharply increased concentrations of glycerol and succinic and malic acids in the fine particles during the haze event were mainly derived from the field burning of wheat straw, although the sources of glucose and related sugar-alcohols whose concentrations significantly increased in the fine haze samples are unclear. Compared to that in the fresh smoke particles of wheat straw burning an increase in relative abundance of succinic acid to levoglucosan during the haze event suggests a significant production of secondary organic aerosols during transport of the smoke plumes.

  2. Airborne measurements of the Eyjafjallajökull volcanic ash plume over northwestern Germany with a light aircraft and an optical particle counter: first results

    NASA Astrophysics Data System (ADS)

    Weber, Konradin; Vogel, Andreas; Fischer, Christian; van Haren, Günther; Pohl, Tobias

    2010-10-01

    During the eruption phase of the Icelandic volcano Eyjafjallajökull in April/May 2010 the University of Applied Sciences Duesseldorf has performed 14 measurement flights over north-western Germany in the time period of 23 April 2010 to 21 May 2010. Additionally 4 flights have been performed for visual observations, referencing and transfer. The measurement flights have been performed in situations, where the ash plume was present over north-western Germany as well as in situations, when there was no ash plume predicted. For the measurements a light aircraft (Flight Design CTSW Shortwing) was used, which was equipped with an optical particle counter (Grimm 1.107). Additionally the aircraft was equipped for one flight with an UV-DOAS system and a CO2-measurement system. The optical particle counter allowed in-situ measurements of the particle distribution between 250 nm and 32 μm and of PM10, PM2.5 and PM1. The ash plume appeared during the measurements as inhomogeneous in structure. Layers or multilayers of one hundred meters to a few hundred meters vertical depth of ash plume could be identified. Sub-plumes with a horizontal extension of several kilometres to several tenths of kilometres could be found. The layers of the ash plume could be found in altitudes between 2500m and 4500m. The measured concentrations have been compared with the concentration and extension of the ash plume predicted by the Volcanic Ash Advisory Centre (VAAC).

  3. Radioactive waste shredding: Preliminary evaluation

    SciTech Connect

    Soelberg, N.R.; Reimann, G.A.

    1994-07-01

    The critical constraints for sizing solid radioactive and mixed wastes for subsequent thermal treatment were identified via a literature review and a survey of shredding equipment vendors. The types and amounts of DOE radioactive wastes that will require treatment to reduce the waste volume, destroy hazardous organics, or immobilize radionuclides and/or hazardous metals were considered. The preliminary steps of waste receipt, inspection, and separation were included because many potential waste treatment technologies have limits on feedstream chemical content, physical composition, and particle size. Most treatment processes and shredding operations require at least some degree of feed material characterization. Preliminary cost estimates show that pretreatment costs per unit of waste can be high and can vary significantly, depending on the processing rate and desired output particle size.

  4. Reactor radioactive emission monitor

    SciTech Connect

    Jester, W.A.; Mc Master, I.B.; Baratta, A.J.

    1987-05-05

    This patent describes a means for measuring quantities of a selected radioactive component in a stream of radioactive fluid. The means comprise: a first fluid path with a first means for retaining the selected radioactive component mounted in the fluid path for retaining the radioactive component while passing the remainder of the stream of radioactive fluid; a second fluid path with a second means for retaining the selected radioactive component mounted in the second fluid path for retaining the radioactive component while passing the remainder of the stream of the radioactive fluid; first and second detectors for detecting the level of radioactivity emitted by the retained radioactive component in the first and second retaining means; a means for integrating the output of one or more of the detectors as a function of time to measure any increase in the radioactivity emitted by the radioactive component retained by the retaining means, and the increase being representative of the amount of selected radioactive component present in the stream of radioactive fluid.

  5. RESRAD. Site-Specific Residual Radioactivity

    SciTech Connect

    Yu, C.

    1989-06-01

    RESRAD is designed to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil. A guideline is defined as a radionuclide concentration or a level of radiation or radioactivity that is acceptable if a site is to be used without radiological restrictions. Guidelines are expressed as (1) concentrations of residual radionuclides in soil, (2) concentrations of airborne radon decay products, (3) levels of external gamma radiation, (4) levels of radioactivity from surface contamination, and (5) concentrations of residual radionuclides in air and water. Soil is defined as unconsolidated earth material, including rubble and debris that may be present. The controlling principles of all guidelines are (1) the annual radiation dose received by a member of the critical population group from the residual radioactive material - predicted by a realistic but reasonably conservative analysis and averaged over a 50 year period - should not exceed 100 mrem/yr, and (2) doses should be kept as low as reasonably achievable. All significant exposure pathways for the critical population group are considered in deriving soil guidelines. These pathways include direct exposure to external radiation from the contaminated soil material; internal radiation from inhalation of airborne radionuclides; and internal radiation from ingestion of plant foods grown in the contaminated soil, meat and milk from livestock fed with contaminated fodder and water, drinking water from a contaminated well, and fish from a contaminated pond.

  6. Promoting Smoke-Free Homes: A Novel Behavioral Intervention Using Real-Time Audio-Visual Feedback on Airborne Particle Levels

    PubMed Central

    Klepeis, Neil E.; Hughes, Suzanne C.; Edwards, Rufus D.; Allen, Tracy; Johnson, Michael; Chowdhury, Zohir; Smith, Kirk R.; Boman-Davis, Marie; Bellettiere, John; Hovell, Melbourne F.

    2013-01-01

    Interventions are needed to protect the health of children who live with smokers. We pilot-tested a real-time intervention for promoting behavior change in homes that reduces second hand tobacco smoke (SHS) levels. The intervention uses a monitor and feedback system to provide immediate auditory and visual signals triggered at defined thresholds of fine particle concentration. Dynamic graphs of real-time particle levels are also shown on a computer screen. We experimentally evaluated the system, field-tested it in homes with smokers, and conducted focus groups to obtain general opinions. Laboratory tests of the monitor demonstrated SHS sensitivity, stability, precision equivalent to at least 1 µg/m3, and low noise. A linear relationship (R2 = 0.98) was observed between the monitor and average SHS mass concentrations up to 150 µg/m3. Focus groups and interviews with intervention participants showed in-home use to be acceptable and feasible. The intervention was evaluated in 3 homes with combined baseline and intervention periods lasting 9 to 15 full days. Two families modified their behavior by opening windows or doors, smoking outdoors, or smoking less. We observed evidence of lower SHS levels in these homes. The remaining household voiced reluctance to changing their smoking activity and did not exhibit lower SHS levels in main smoking areas or clear behavior change; however, family members expressed receptivity to smoking outdoors. This study established the feasibility of the real-time intervention, laying the groundwork for controlled trials with larger sample sizes. Visual and auditory cues may prompt family members to take immediate action to reduce SHS levels. Dynamic graphs of SHS levels may help families make decisions about specific mitigation approaches. PMID:24009742

  7. A comparison between different high volume sampling systems for collecting ambient airborne particles for mutagenicity testing and for analysis of organic compounds.

    PubMed

    Alfheim, I; Lindskog, A

    1984-03-15

    Samples of urban air were collected simultaneously using different sampling systems, including electrostatic precipitation (ESP) and high volume filtration (HVF) on various filters for particle sampling and absorption on activated carbon and organic polymers for sampling of volatiles. Acetone extracts of the samples were analyzed for polycyclic aromatic hydrocarbons (PAH) and tested for mutagenicity with the Ames Salmonella/microsome assay. The results show that the concentrations of PAH found in the various particle-samples were in good agreement, whereas the mutagenic activity of these samples showed large variations. The highest mutagenic activity was found in the samples collected by ESP and on the teflon-coated glassfibre filters, whereas samples collected by high volume filtration with size-fractionation showed the lowest mutagenic activity. We do not know whether the higher activity in samples from the teflon-coated filters compared to those from ordinary glassfibre filters represent filter artifacts or if it represents a more pronounced degradation of mutagenic compounds on the non-coated glassfibre filters. Extracts from filter blanks seemed to interfere with the expression of the mutagenic activity of the positive controls, benzo[a]pyrene and nitropyrene. When sampling volatile compounds, two organic polymers, polyurethane (PUR) and XAD-2, were found suitable for collecting PAH, whereas no PAH could be detected in extracts from the activated carbon. The XAD-2 adsorbent was the most effective for sampling bicyclic PAH. None of the adsorbents yielded extracts well suited for mutagenicity testing, since blank extracts were toxic to the test bacteria. Some extracts of the PUR blanks were weakly mutagenic as well. More emphasis should be placed upon developing more efficient and unreactive adsorbents and on the adaptation of such adsorbents in samplers suited for routine use.

  8. Airborne Particulate Threat Assessment

    SciTech Connect

    Patrick Treado; Oksana Klueva; Jeffrey Beckstead

    2008-12-31

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

  9. Airborne gamma spectrometry--towards integration of European operational capability.

    PubMed

    Toivonen, Harri

    2004-01-01

    Airborne gamma spectrometry is an excellent tool for finding out in a timely manner the extent and magnitude of the dispersion of radioactive materials resulting from a nuclear disaster. To utilise existing European airborne monitoring capabilities for multilateral assistance in an accident is a complex administrative and technical matter. Several international exercises have been organised demonstrating the capability to cooperate. However, efficient mutual assistance between European countries requires conceptual work, standards and harmonisation of software. A unified radiological vocabulary and data exchange format in XML need to be developed. A comprehensive database is essential for data assimilation. An operations centre is needed for management and planning of surveys.

  10. Magnetic characterization of airborne particulates

    NASA Astrophysics Data System (ADS)

    Kim, W.; Doh, S.; Yu, Y.

    2010-12-01

    Burning fossil fuels from vehicles, domestics, industries and power plants in the large urban or industrial areas emit significant quantity of anthropogenic particulates which become a potential threat to human health. Here, we present temporal variability of particulate pollution associated with compositional differences, using magnetic measurements and electron microscopic observations. Six different grain-sizes of airborne particulates have been collected by filtering from 10 precipitation events in Seoul, Korea from February 2009 to June 2009. Magnetic concentration proxies show relatively better (R2 >0.6) and poorer correlations (R2 <0.3) with the masses of samples filtered by >0.45 μm and <0.45 μm sizes, respectively, suggesting the usefulness of magnetic characterization for the >0.45 μm particulates. Temporally, magnetic concentrations are higher in the cold season than the warm season. In particular, a significant increase of magnetic concentration is observed in 3 μm and 1 μm filters after the Chinese wind-blown dust events, indicating additional influx of fine-grained anthropogenic particulates into Seoul. Microscopic observations identify that increase of magnetic concentration is highly linked with the frequent occurrence of combustion derived particulates (i.e., carbon and/or sulfur mixed particles) than natural alumino-silicates. Overall, the present study demonstrates that magnetic measurements efficiently reflect the concentration of particulates produced from fossil-fuel combustion among the airborne particles from various sources.

  11. Radioactive diagnostic agent

    SciTech Connect

    Shigematsu, A.; Aihara, M.; Matsuda, M.; Suzuki, A.; Tsuya, A.

    1984-02-07

    A radioactive diagnostic agent for renal cortex, adrenal cortex, myocardium, brain stem, spinal nerve, etc., which comprises as an essential component monoiodoacetic acid wherein the iodine atom is radioactive.

  12. Radioactive Iodine (Radioiodine) Therapy

    MedlinePlus

    ... and Stage Thyroid Cancer Treating Thyroid Cancer Radioactive Iodine (Radioiodine) Therapy for Thyroid Cancer Your thyroid gland absorbs nearly all of the iodine in your body. When radioactive iodine (RAI), also ...

  13. Levels, indoor-outdoor relationships and exposure risks of airborne particle-associated perchlorate and chlorate in two urban areas in Eastern Asia.

    PubMed

    Yao, Lan; Yang, Lingxiao; Chen, Jianmin; Toda, Kei; Wang, Xinfeng; Zhang, Junmei; Yamasaki, Dai; Nakamura, Yukihide; Sui, Xiao; Zheng, Longfei; Wen, Liang; Xu, Caihong; Wang, Wenxing

    2015-09-01

    Indoor and outdoor concentrations of PM2.5-associated perchlorate (ClO4(-)) and chlorate (ClO3(-)) were investigated in Jinan, China, and size-resolved perchlorate and chlorate were studied in Kumamoto, Japan. The average outdoor PM2.5-associated concentrations of perchlorate and chlorate were 4.18 ng m(-3) and 2.82 ng m(-3), respectively, in Jinan. Perchlorate and chlorate were mainly distributed in fine particles, and their approximate PM2.5-associated concentrations were 0.04 ng m(-3) and 4.14 ng m(-3), respectively, in Kumamoto. The ratios of ClO3(-)/ClO4(-) ranged from 18.72 to 360.22 in Kumamoto and from 0.03 to 7.45 in Jinan. The highest concentration of perchlorate (173.76 ng m(-3)) was observed on Spring Festival Eve. This finding and the significant correlation between perchlorate and fireworks-related components (Cl(-) and K(+)) indicated that the fireworks display was a significant source of perchlorate in Jinan. The indoor concentrations of perchlorate and chlorate in Jinan were 3.54 ng m(-3) (range, 0.14-125.14 ng m(-3)) and 0.94 ng m(-3) (range, 0.10-1.80 ng m(-3)), respectively. In the absence of an indoor source of perchlorate, the occurrence of indoor concentrations higher than those found outdoors was a common effect of individual fireworks displays near the sampling sites, coupled with meteorological influences and poor indoor diffusion conditions. The exposure risks of perchlorate and chlorate indoors indicated that the potential risk of perchlorate exposure to children during fireworks displays is deserving of concern.

  14. Airborne gravity is here

    SciTech Connect

    Hammer, S.

    1982-01-11

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

  15. Tilted foil polarization of radioactive beam nuclei

    NASA Astrophysics Data System (ADS)

    Goldring, Gvirol

    1992-11-01

    Tilted foil polarization has up to now been mostly applied to nuclear reaction products recoiling out of a target traversed by a primary particle beam. Being a universal phenomenon it can be applied equally well to beams of particles, primary or secondary, radioactive or other. There are however some technical considerations arising from the nature of the beam particles. Radioactive beams are associated with ground state nuclei. They usually have low nuclear spin and as a consequence-as will be shown later-low polarization. Secondary beams are usually low in intensity and do not impose any constraints on the foils they traverse; unlike intense primary heavy ion beams which, if they traverse the foils, essentially limit the foil material to carbon. We review here briefly the tilted foil polarization process and then discuss an experiment with an isomer beam. Finally we review experiments with radioactive beams, past, present and planned for the future.

  16. NEW APPROACHES: Radioactive balloons: experiments on radon concentration in schools or homes

    NASA Astrophysics Data System (ADS)

    Austen, David; Brouwer, Wytze

    1997-03-01

    Balloons that have been rubbed to create a charge will attract radioactive dust particles in an ordinary laboratory in sufficient numbers to allow students to measure the radioactivity and also the effective half-life.

  17. Dissolution and clearance of titanium tritide particles in the lungs of F344/Crl rats

    SciTech Connect

    Cheng, Yung-Sung; Snipes, M.B.; Wang, Yansheng

    1995-12-01

    Metal tritides are compounds in which the radioactive isotope tritium, following adsorption onto the metal, forms a stable chemical compound with the metal. When particles of tritiated metals become airborne, they can be inhaled by workers. Because the particles may be retained in the lung for extended periods, the resulting dose will be greater than doses following exposure to tritium gas or tritium oxide (HTO). Particles of triated metals may be dispersed into the air during routine handling, disruption of contaminated metals, or as a result of spontaneous radioactive decay processes. Unlike metal hydrides and deuterides, tritides are radioactive, and the decay of the tritium atoms affects the metal. Because helium is a product of the decay, helium bubbles form within the metal tritide matrix. The pressure from these bubbles leads to respirable particles breaking off from the tritide surface. Our results show that a substantial amount of titanium tritide remains in the rat lung 10 d after intratracheal instillation, confirming results previously obtain in an in vitro dissolution study.

  18. Towards airborne nanoparticle mass spectrometry with nanomechanical string resonators

    NASA Astrophysics Data System (ADS)

    Schmid, Silvan; Kurek, Maksymilian; Boisen, Anja

    2013-06-01

    Airborne nanoparticles can cause severe harm when inhaled. Therefore, small and cheap portable airborne nanoparticle monitors are highly demanded by authorities and the nanoparticle producing industry. We propose to use nanomechanical resonators to build the next generation cheap and portable airborne nanoparticle sensors. Recently, nanomechanical mass spectrometry was established. One of the biggest challenges of nanomechanical sensors is the low efficiency of diffusion-based sampling. We developed an inertial-based sampling method that enables the efficient sampling of airborne nanoparticles on a nanomechanical sensor operating directly in air. We measured a sampling rate of over 1000 particles per second, for 28 nm silica nanoparticles with a concentration of 380000 #/cm3, collected on a 500 nm wide nanomechanical string resonator. We show that it is possible to reach a saturated sampling regime in which 100% of all nanoparticles are captured that are owing in the projection of the nanostring. We further show that it is possible to detect single airborne nanoparticles by detecting 50 nm Au particles with a 250 nm wide string resonator. Our resonators are currently operating in the first bending mode. Mass spectrometry of airborne nanoparticles requires the simultaneous operation in the first and second mode, which can be implemented in the transduction scheme of the resonator. The presented results lay the cornerstone for the realization of a portable airborne nanoparticle mass spectrometer.

  19. Progress on detection of radioactivity by airborne equipment

    USGS Publications Warehouse

    Stead, Frank W.

    1949-01-01

    Coincidence and anti-coincidence counting rate meters and also an air conductivity meter have been installed in a transport plane to measure gamma radiation from ground sources. Materials containing 0.01 percent uranium can be detected at 500 feet and at an airspeed of 150 miles per hour.

  20. Effects of airborne particulates on remote spectrometry data collected for industrial accident response support

    NASA Astrophysics Data System (ADS)

    Lewis, Paul E.

    2003-12-01

    The Environmental Protection Agency (EPA) Region 7 maintains an operational passive midwave/longwave airborne spectrometer system. This system provides near-real-time information on hazardous chemical releases (e.g., chemical constituents, column density and direction) for emergency personnel responding to industrial accidents. Industrial accidents range from ruptured tank cars caused by train derailments to explosions at industrial facilities. Airborne particles may be present as well, especially in accidents involving explosions and fire. This paper investigates how the presence of airborne particles can affect the identification of airborne chemical species in these situations.

  1. Effects of airborne particulates on remote spectrometry data collected for industrial accident response support

    NASA Astrophysics Data System (ADS)

    Lewis, Paul E.

    2004-01-01

    The Environmental Protection Agency (EPA) Region 7 maintains an operational passive midwave/longwave airborne spectrometer system. This system provides near-real-time information on hazardous chemical releases (e.g., chemical constituents, column density and direction) for emergency personnel responding to industrial accidents. Industrial accidents range from ruptured tank cars caused by train derailments to explosions at industrial facilities. Airborne particles may be present as well, especially in accidents involving explosions and fire. This paper investigates how the presence of airborne particles can affect the identification of airborne chemical species in these situations.

  2. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; Hiroshi, Nakashima; Yukio, Sakamoto; Hiroshi, Matsumura; Hiroshi, Iwase; Norikazu, Kinoshita; David, Boehnlein; Gary, Lautenschlager; Anthony, Leveling; Nikolai, Mokhov; Kamran, Vaziri; Koji, Oishi

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  3. Shielding experiments by the JASMIN collaboration at Fermilab (II) - Radioactivity measurement induced by secondary particles from the anti-proton production target

    SciTech Connect

    Yashima, Hiroshi; Matsuda, Norihiro; Kasugai, Yoshimi; Matsumura, Hiroshi; Iwase, Hiroshi; Kinoshita, Norikazu; Boehnlein, David; Lauten, Gary; Leveling, Anthony; Mokhov, Nikolai; Vaziri, Kamran; /Fermilab /Shimizu, Tokyo /JAEA, Ibaraki

    2011-01-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 10{sub 12} protons per second. Samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured by studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.

  4. Shielding experiments by the JASMIN Collaboration at Fermilab (II) - radioactivity measurement induced by secondary particles from the anti-proton production target

    DOE PAGES

    Hiroshi, Yashima; Norihiro, Matsuda; Yoshimi, Kasugai; ...

    2011-08-01

    The JASMIN Collaboration has performed an experiment to conduct measurements of nuclear reaction rates around the anti-proton production (Pbar) target at the Fermi National Accelerator Laboratory (FNAL). At the Pbar target station, the target, consisting of an Inconel 600 cylinder, was irradiated by a 120 GeV/c proton beam from the FNAL Main Injector. The beam intensity was 3.6 x 1012 protons per second. The samples of Al, Nb, Cu, and Au were placed near the target to investigate the spatial and energy distribution of secondary particles emitted from it. After irradiation, the induced activities of the samples were measured bymore » studying their gamma ray spectra using HPGe detectors. The production rates of 30 nuclides induced in Al, Nb, Cu, Au samples were obtained. These rates increase for samples placed in a forward (small angle) position relative to the target. The angular dependence of these reaction rates becomes larger for increasing threshold energy. These experimental results are compared with Monte Carlo calculations. The calculated results generally agree with the experimental results to within a factor of 2 to 3.« less

  5. Modelling the risk of airborne infectious disease using exhaled air.

    PubMed

    Issarow, Chacha M; Mulder, Nicola; Wood, Robin

    2015-05-07

    In this paper we develop and demonstrate a flexible mathematical model that predicts the risk of airborne infectious diseases, such as tuberculosis under steady state and non-steady state conditions by monitoring exhaled air by infectors in a confined space. In the development of this model, we used the rebreathed air accumulation rate concept to directly determine the average volume fraction of exhaled air in a given space. From a biological point of view, exhaled air by infectors contains airborne infectious particles that cause airborne infectious diseases such as tuberculosis in confined spaces. Since not all infectious particles can reach the target infection site, we took into account that the infectious particles that commence the infection are determined by respiratory deposition fraction, which is the probability of each infectious particle reaching the target infection site of the respiratory tracts and causing infection. Furthermore, we compute the quantity of carbon dioxide as a marker of exhaled air, which can be inhaled in the room with high likelihood of causing airborne infectious disease given the presence of infectors. We demonstrated mathematically and schematically the correlation between TB transmission probability and airborne infectious particle generation rate, ventilation rate, average volume fraction of exhaled air, TB prevalence and duration of exposure to infectors in a confined space.

  6. Technical basis for removal of 221-T tunnel from airborne radiological area status

    SciTech Connect

    Geuther, W.J., Westinghouse Hanford

    1996-08-30

    This document provides the technical basis for removal of the 221-T Tunnel from airborne radiological control. T Plant Radiological Control has evaluated air sampling data and engineering controls, and determined the necessary administrative controls to make this transition. With these administrative controls (specified within document) in place, the tunnel can be removed from Airborne Radioactive Area status. The removal of the tunnel from airborne status will allow work to be performed within the tunnel under controlled conditions, as outlined in this technical basis, without the use of respiratory protection equipment.

  7. An aerial survey of radioactivity associated with Atomic Energy plants

    SciTech Connect

    Davis, F.J.; Harlan, W.E.; Humphrey, P.A.; Kane, R.L.; Reinhardt, P.W.

    1992-09-02

    The project covered was an endeavor to (1) compare a group of laboratory instruments as airborne detectors of radioactivity and (2) simultaneously obtain data relative to the diffusion rate of radioactive contamination emitted into the atmosphere from off-gas stacks of production runs. Research was conducted in the Oak Ridge, Tennessee and Hanford, Washington areas. Detection was accomplished at a maximum distance of seventeen miles from the plant. Very little information of a conclusive nature was gained concerning the diffusion. Further research with the nuclear instruments, using a stronger source, is recommended. To obtain conclusive information concerning the meteorological aspects of the project, a larger observational program will be needed.

  8. 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.

  9. Airborne Next: Rethinking Airborne Organization and Applying New Concepts

    DTIC Science & Technology

    2015-06-01

    structures since its employment on a large scale during World War II. It is puzzling to consider how little airborne organizational structures and employment...future potential of airborne concepts by rethinking traditional airborne organizational structures and employment concepts. Using a holistic approach in... structures of airborne forces to model a “small and many” approach over a “large and few” approach, while incorporating a “swarming” concept. Utilizing

  10. DO AIRBORNE PARTICLES INDUCE HERITABLE MUTATIONS?

    EPA Science Inventory

    Urban air is contaminated by gaseous and particulate emissions from a variety of sources, including industrial, vehicular, power generation, and natural. These emissions, as well as their atmospheric transformation products, damage ecological systems and causes adverse effects on...

  11. ORNL radioactive waste operations

    SciTech Connect

    Sease, J.D.; King, E.M.; Coobs, J.H.; Row, T.H.

    1982-01-01

    Since its beginning in 1943, ORNL has generated large amounts of solid, liquid, and gaseous radioactive waste material as a by-product of the basic research and development work carried out at the laboratory. The waste system at ORNL has been continually modified and updated to keep pace with the changing release requirements for radioactive wastes. Major upgrading projects are currently in progress. The operating record of ORNL waste operation has been excellent over many years. Recent surveillance of radioactivity in the Oak Ridge environs indicates that atmospheric concentrations of radioactivity were not significantly different from other areas in East Tennesseee. Concentrations of radioactivity in the Clinch River and in fish collected from the river were less than 4% of the permissible concentration and intake guides for individuals in the offsite environment. While some radioactivity was released to the environment from plant operations, the concentrations in all of the media sampled were well below established standards.

  12. Radioactivity and food

    SciTech Connect

    Olszyna-Marzys, A.E. )

    1990-03-01

    Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references.

  13. Radioactive materials released from nuclear power plants. Annual report 1978

    SciTech Connect

    Tichler, J.; Benkovitz, C.

    1981-03-01

    Releases of radioactive materials in airborne and liquid effluents from commerical light water reactors during 1978 have been compiled and reported. Data on soild waste shipments as well as selected operating information have been included. This report supplements earlier annual reports by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1978 release data are compared with previous years releases in tabular form. Data covering specific radionuclides are summarized.

  14. Radioactive Waste Management Basis

    SciTech Connect

    Perkins, B K

    2009-06-03

    The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  15. Radioactive Wastes. Revised.

    ERIC Educational Resources Information Center

    Fox, Charles H.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. This booklet deals with the handling, processing and disposal of radioactive wastes. Among the topics discussed are: The Nature of Radioactive Wastes; Waste Management; and Research and Development. There are…

  16. Radioactive waste disposal package

    DOEpatents

    Lampe, Robert F.

    1986-11-04

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  17. Temporary Personal Radioactivity

    NASA Astrophysics Data System (ADS)

    Myers, Fred

    2012-11-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances.

  18. Radioactive waste disposal package

    DOEpatents

    Lampe, Robert F.

    1986-01-01

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  19. A Remote Radioactivity Experiment

    ERIC Educational Resources Information Center

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one…

  20. Hot particles in the environment: assessment of dose and health detriment.

    PubMed

    Burkart, W; Linder, H

    1987-01-01

    Hot particles, highly radioactive particles made up of fission products or actinides and being small enough to become airborne, defy many of the dose models and risk concepts in use by the health physics community. At environmental exposures, both on the level of populations and tissues, dose distributions become very skewed; only few persons or tissue cells being exposed at correspondingly higher levels. Fallout from Chernobyl showed a numerically small subfraction of the aerosol particles containing activities of up to 10 kBq 103-ruthenium or up to 0.3 Bq 242-curium in single particles. The implications of these hot particles on the dosimetry after uptake are great since the locally accumulated dose, for example in the pulmonary region, may reach up to 10 MSv. For inhalation as well as for ingestion, theoretical considerations predict a decrease in the effectiveness of particulate radioactivity as compared to monomeric activity. This hypothesis is also supported by experimental and epidemiological evidence from the examination of the radiation effects of particulate alpha-emitters deposited in the lung.

  1. International Symposium on Airborne Geophysics

    NASA Astrophysics Data System (ADS)

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

    2006-05-01

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

  2. Radioactive Iodine Treatment for Hyperthyroidism

    MedlinePlus

    ... Balance › Radioactive Iodine for Hyperthyroidism Fact Sheet Radioactive Iodine for Hyperthyroidism April, 2012 Download PDFs English Zulu ... prepare for RAI or surgery. How does radioactive iodine treatment work? Iodine is important for making thyroid ...

  3. Airborne Remote Sensing

    NASA Technical Reports Server (NTRS)

    1992-01-01

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

  4. Recognizing Airborne Hazards.

    ERIC Educational Resources Information Center

    Schneider, Christian M.

    1990-01-01

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

  5. Airborne asbestos in buildings.

    PubMed

    Lee, R J; Van Orden, D R

    2008-03-01

    The concentration of airborne asbestos in buildings nationwide is reported in this study. A total of 3978 indoor samples from 752 buildings, representing nearly 32 man-years of sampling, have been analyzed by transmission electron microscopy. The buildings that were surveyed were the subject of litigation related to suits alleging the general building occupants were exposed to a potential health hazard as a result the presence of asbestos-containing materials (ACM). The average concentration of all airborne asbestos structures was 0.01structures/ml (s/ml) and the average concentration of airborne asbestos > or = 5microm long was 0.00012fibers/ml (f/ml). For all samples, 99.9% of the samples were <0.01 f/ml for fibers longer than 5microm; no building averaged above 0.004f/ml for fibers longer than 5microm. No asbestos was detected in 27% of the buildings and in 90% of the buildings no asbestos was detected that would have been seen optically (> or = 5microm long and > or = 0.25microm wide). Background outdoor concentrations have been reported at 0.0003f/ml > or = 5microm. These results indicate that in-place ACM does not result in elevated airborne asbestos in building atmospheres approaching regulatory levels and that it does not result in a significantly increased risk to building occupants.

  6. Determination of airborne nanoparticles from welding operations.

    PubMed

    Gomes, João Fernando Pereira; Albuquerque, Paula Cristina Silva; Miranda, Rosa Maria Mendes; Vieira, Maria Teresa Freire

    2012-01-01

    The aim of this study is to assess the levels of airborne ultrafine particles emitted in welding processes (tungsten inert gas [TIG], metal active gas [MAG] of carbon steel, and friction stir welding [FSW] of aluminum) in terms of deposited area in pulmonary alveolar tract using a nanoparticle surface area monitor (NSAM) analyzer. The obtained results showed the dependence of process parameters on emitted ultrafine particles and demonstrated the presence of ultrafine particles compared to background levels. Data indicated that the process that resulted in the lowest levels of alveolar deposited surface area (ADSA) was FSW, followed by TIG and MAG. However, all tested processes resulted in significant concentrations of ultrafine particles being deposited in humans lungs of exposed workers.

  7. Photoreactivation in Airborne Mycobacterium parafortuitum

    PubMed Central

    Peccia, Jordan; Hernandez, Mark

    2001-01-01

    Photoreactivation was observed in airborne Mycobacterium parafortuitum exposed concurrently to UV radiation (254 nm) and visible light. Photoreactivation rates of airborne cells increased with increasing relative humidity (RH) and decreased with increasing UV dose. Under a constant UV dose with visible light absent, the UV inactivation rate of airborne M. parafortuitum cells decreased by a factor of 4 as RH increased from 40 to 95%; however, under identical conditions with visible light present, the UV inactivation rate of airborne cells decreased only by a factor of 2. When irradiated in the absence of visible light, cellular cyclobutane thymine dimer content of UV-irradiated airborne M. parafortuitum and Serratia marcescens increased in response to RH increases. Results suggest that, unlike in waterborne bacteria, cyclobutane thymine dimers are not the most significant form of UV-induced DNA damage incurred by airborne bacteria and that the distribution of DNA photoproducts incorporated into UV-irradiated airborne cells is a function of RH. PMID:11526027

  8. Simulation of atmospheric dispersion of radioactivity from the Chernobyl accident

    SciTech Connect

    Lange, R.; Sullivan, T.J.; Gudiksen, P.H. )

    1989-07-01

    Measurements of airborne radioactivity over Europe, Japan, and the United States indicated that the release from the Chernobyl reactor accident in the Soviet Union on April 26, 1986 contained a wide spectrum of fission up to heights of 7 km or more within a few days after the initial explosion. This high-altitude presence of radioactivity would in part be attributable to atmospheric dynamics factors other than the thermal energy released in the initial explosion. Indications were that two types of releases had taken place -- an initial powerful explosion followed by days of a less energetic reactor fire. The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) utilized three-dimensional atmospheric dispersion models to determine the characteristics of the source term (release) and the evolution of the spatial distributions of the airborne radioactivity as it was transported over Europe and subsequently over the northern hemisphere. This paper describes the ARAC involvement and the results of the hemispheric model calculations which graphically depict the extensive dispersal of radioactivity. 1 fig.

  9. Pump station for radioactive waste water

    SciTech Connect

    Whitton, John P.; Klos, Dean M.; Carrara, Danny T.; Minno, John J.

    2003-11-18

    A pump station for transferring radioactive particle containing waste water, includes: (a.) an enclosed sump having a vertically elongated right frusto conical wall surface and a bottom surface and (b.) a submersible volute centrifugal pump having a horizontally rotating impeller and a volute exterior surface. The sump interior surface, the bottom surface and the volute exterior surface are made of stainless steel having a 30 Ra or finer surface finish. A 15 Ra finish has been found to be most cost effective. The pump station is used for transferring waste water, without accumulation of radioactive fines.

  10. Particle preconcentrator

    DOEpatents

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    2000-01-01

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  11. Particle preconcentrator

    SciTech Connect

    Linker, K.L.; Conrad, F.J.; Custer, C.A.; Rhykerd, C.L. Jr.

    1998-12-29

    An apparatus and method are disclosed for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents. 3 figs.

  12. Particle preconcentrator

    SciTech Connect

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    1998-01-01

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  13. Particle preconcentrator

    SciTech Connect

    Linker, Kevin L.; Conrad, Frank J.; Custer, Chad A.; Rhykerd, Jr., Charles L.

    2005-09-20

    An apparatus and method for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a pervious screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  14. Particle preconcentrator

    SciTech Connect

    Linker, K.L.; Conrad, F.J.; Custer, C.A.; Rhykerd, C.L. Jr

    2000-07-11

    An apparatus and method are disclosed for preconcentrating particles and vapors. The preconcentrator apparatus permits detection of highly diluted amounts of particles in a main gas stream, such as a stream of ambient air. A main gas stream having airborne particles entrained therein is passed through a previous screen. The particles accumulate upon the screen, as the screen acts as a sort of selective particle filter. The flow of the main gas stream is then interrupted by diaphragm shutter valves, whereupon a cross-flow of carrier gas stream is blown parallel past the faces of the screen to dislodge the accumulated particles and carry them to a particle or vapor detector, such as an ion mobility spectrometer. The screen may be heated, such as by passing an electrical current there through, to promote desorption of particles therefrom during the flow of the carrier gas. Various types of screens are disclosed. The apparatus and method of the invention may find particular utility in the fields of narcotics, explosives detection and chemical agents.

  15. Characterisation of particulate matter on airborne pollen grains.

    PubMed

    Ribeiro, Helena; Guimarães, Fernanda; Duque, Laura; Noronha, Fernando; Abreu, Ilda

    2015-11-01

    A characterization of the physical-chemical composition of the atmospheric PM adsorbed to airborne pollen was performed. Airborne pollen was sampled using a Hirst-type volumetric spore sampler and observed using a Field Emission Electron Probe Microanalyser for PM analysis. A secondary electron image was taken of each pollen grain and EDS spectra were obtained for individually adsorbed particles. All images were analysed and the size parameters of the particles adsorbed to pollen was determined. The measured particles' equivalent diameter varied between 0.1 and 25.8 μm, mostly in the fine fraction. The dominant particulates identified were Si-rich, Organic-rich, SO-rich, Metals & Oxides and Cl-rich. Significant daily differences were observed in the physical-chemical characteristics of particles adsorbed to the airborne pollen wall. These differences were correlated with weather parameters and atmospheric PM concentration. Airborne pollen has the ability to adsorb fine particles that may enhance its allergenicity.

  16. Effects of fluvial processes in different order river valleys on redistribution and storage of particle-bound radioactive caesium-137 in area of significant Chernobyl fallout and impact on linked rivers with lower contamination levels

    NASA Astrophysics Data System (ADS)

    Belyaev, Vladimir; Golosov, Valentin; Shamshurina, Evgeniya; Ivanov, Maxim; Ivanova, Nadezhda; Bezukhov, Dmitry; Onda, Yuichi; Wakiyama, Yoshifumi; Evrard, Olivier

    2015-04-01

    Detailed investigations of the post-fallout fate of radionuclide contamination represent an important task in terms of environmental quality assessment. In addition, particle-bound radionuclides such as the most widespread anthropogenic isotope caesium-137 can be used as tracers for quantitative assessment of different sediment redistribution processes. In landscapes of humid plains with agriculture-dominated land use the post-fallout redistribution of caesium-137 is primarily associated with fluvial activity of various scales in cascade systems starting from soil erosion on cultivated hillslopes through gully and small dry valley network into different order perennial streams and rivers. Our investigations in the so-called Plavsk hotspot (area of very high Chernobyl caesium-137 contamination within the Plava River basin, Tula Region, Central European Russia) has been continuing for more than 15 years by now, while the time passed since the Chernobyl disaster and associated radioactive fallout (1986) is almost 29 years. Detailed information on the fluvial sediment and associated caesium-137 redistribution has been obtained for case study sites of different size from individual cultivated slopes and small catchments of different size (2-180 km2) to the entire Plava River basin scale (1856 km2). It has been shown that most of the contaminated sediment over the time passed since the fallout has remained stored within the small dry valleys of the 1-4 Hortonian order and local reservoirs (>70%), while only about 5% reached the 5-6 order valleys (main tributaries of the Plava River) and storage of the Plava floodplain itself represents as low as 0.3% of the basin-scale total sediment production from eroded cultivated hillslopes. Nevertheless, it has been shown that contaminated sediment yield from the Plava River basin exerts significant influence on less polluted downstream-linked river system. Recent progress of the investigations involved sampling of 7 detailed depth

  17. A Remote Radioactivity Experiment

    NASA Astrophysics Data System (ADS)

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one of us (MV) worked at, and after talking with numerous colleagues we know this is still the case at many schools. What options are there then for physics teachers to allow their students to experimentally investigate certain characteristics of radioactivity, such as how distance affects the intensity of radiation coming from a radioactive source? There are computer simulations that can be run, or perhaps the teacher has a light sensor and tries to make an analogy between the intensity of light from a light bulb and the intensity of radiation from a radioactive source based on geometric arguments to get an inverse-square law. But for many there is no direct experimental option if one does not possess a Geiger counter and good radioactive sample. It is for that teacher and class of students that an online, remote radioactivity experiment was created.

  18. Absolute airborne gravimetry

    NASA Astrophysics Data System (ADS)

    Baumann, Henri

    This work consists of a feasibility study of a first stage prototype airborne absolute gravimeter system. In contrast to relative systems, which are using spring gravimeters, the measurements acquired by absolute systems are uncorrelated and the instrument is not suffering from problems like instrumental drift, frequency response of the spring and possible variation of the calibration factor. The major problem we had to resolve were to reduce the influence of the non-gravitational accelerations included in the measurements. We studied two different approaches to resolve it: direct mechanical filtering, and post-processing digital compensation. The first part of the work describes in detail the different mechanical passive filters of vibrations, which were studied and tested in the laboratory and later in a small truck in movement. For these tests as well as for the airborne measurements an absolute gravimeter FG5-L from Micro-G Ltd was used together with an Inertial navigation system Litton-200, a vertical accelerometer EpiSensor, and GPS receivers for positioning. These tests showed that only the use of an optical table gives acceptable results. However, it is unable to compensate for the effects of the accelerations of the drag free chamber. The second part describes the strategy of the data processing. It is based on modeling the perturbing accelerations by means of GPS, EpiSensor and INS data. In the third part the airborne experiment is described in detail, from the mounting in the aircraft and data processing to the different problems encountered during the evaluation of the quality and accuracy of the results. In the part of data processing the different steps conducted from the raw apparent gravity data and the trajectories to the estimation of the true gravity are explained. A comparison between the estimated airborne data and those obtained by ground upward continuation at flight altitude allows to state that airborne absolute gravimetry is feasible and

  19. Particle Sizer

    NASA Technical Reports Server (NTRS)

    1987-01-01

    Microspheres are tiny plastic beads that represent the first commercial products manufactured in orbit. An example of how they are used is a new aerodynamic particle sizer designated APS 33B produced by TSI Incorporated. TSI purchased the microspheres from the National Bureau of Standards which certified their exact size and the company uses them in calibration of the APS 33B* instrument, latest in a line of TSI systems for generating counting and weighing minute particles of submicron size. Instruments are used for evaluating air pollution control devices, quantifying environments, meteorological research, testing filters, inhalation, toxicology and other areas where generation or analysis of small airborne particles is required. * The APS 33B is no longer being manufactured. An improved version, APS 3320, is now being manufactured. 2/28/97

  20. Membrane technologies for liquid radioactive waste treatment

    NASA Astrophysics Data System (ADS)

    Chmielewski, A. G.; Harasimowicz, M.; Zakrzewska-Trznadel, G.

    1999-01-01

    The paper deals with some problems concerning reduction of radioactivity of liquid low-level nuclear waste streams (LLLW). The membrane processes as ultrafiltration (UF), seeded ultrafiltration (SUF), reverse osmosis (RO) and membrane distillation (MD) were examined. Ultrafiltration enables the removal of particles with molecular weight above cut-off of UF membranes and can be only used as a pre-treatment stage. The improvement of removal is achieved by SUF, employing macromolecular ligands binding radioactive ions. The reduction of radioactivity in LLLW to very low level were achieved with RO membranes. The results of experiments led the authors to the design and construction of UF+2RO pilot plant. The development of membrane distillation improve the selectivity of membrane process in some cases. The possibility of utilisation of waste heat from cooling system of nuclear reactors as a preferable energy source can significantly reduce the cost of operation.

  1. Human Occupancy as a Source of Indoor Airborne Bacteria

    PubMed Central

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

    2012-01-01

    Exposure to specific airborne bacteria indoors is linked to infectious and noninfectious adverse health outcomes. However, the sources and origins of bacteria suspended in indoor air are not well understood. This study presents evidence for elevated concentrations of indoor airborne bacteria due to human occupancy, and investigates the sources of these bacteria. Samples were collected in a university classroom while occupied and when vacant. The total particle mass concentration, bacterial genome concentration, and bacterial phylogenetic populations were characterized in indoor, outdoor, and ventilation duct supply air, as well as in the dust of ventilation system filters and in floor dust. Occupancy increased the total aerosol mass and bacterial genome concentration in indoor air PM10 and PM2.5 size fractions, with an increase of nearly two orders of magnitude in airborne bacterial genome concentration in PM10. On a per mass basis, floor dust was enriched in bacterial genomes compared to airborne particles. Quantitative comparisons between bacterial populations in indoor air and potential sources suggest that resuspended floor dust is an important contributor to bacterial aerosol populations during occupancy. Experiments that controlled for resuspension from the floor implies that direct human shedding may also significantly impact the concentration of indoor airborne particles. The high content of bacteria specific to the skin, nostrils, and hair of humans found in indoor air and in floor dust indicates that floors are an important reservoir of human-associated bacteria, and that the direct particle shedding of desquamated skin cells and their subsequent resuspension strongly influenced the airborne bacteria population structure in this human-occupied environment. Inhalation exposure to microbes shed by other current or previous human occupants may occur in communal indoor environments. PMID:22529946

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

    PubMed

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

    2012-01-01

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

  3. Understanding radioactive waste

    SciTech Connect

    Murray, R.L.

    1981-12-01

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes). (ATT)

  4. Airborne Intercept Monitoring

    DTIC Science & Technology

    2006-04-01

    Primary mirror of Zerodur with Pilkington 747 coating • FOV = 0.104 degrees Airborne Intercept Monitoring RTO-MP-SET-105 16 - 3 UNCLASSIFIED...Pointing System (SPS). The STS is a 0.75 meter aperture Mersenne Cassegrain telescope and the SAT is a 0.34 meter aperture 3- mirror anastigmat telescope...UNLIMITED UNCLASSIFIED/UNLIMITED • Air Flow to Mitigate Thermal “Seeing” Effects • Light weighted primary mirror to reduce mass The SAT

  5. Airborne forest fire research

    NASA Technical Reports Server (NTRS)

    Mattingly, G. S.

    1974-01-01

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

  6. Airborne Infrared Astronomical Telescopes

    NASA Astrophysics Data System (ADS)

    Erickson, Edwin F.

    2017-01-01

    A unique program of infrared astronomical observations from aircraft evolved at NASA’s Ames Research Center, beginning in the 1960s. Telescopes were flown on a Convair 990, a Lear Jet, and a Lockheed C-141 - the Kuiper Airborne Observatory (KAO) - leading to the planning and development of SOFIA: a 2.7 m telescope now flying on a Boeing 747SP. The poster describes these telescopes and highlights of some of the scientific results obtained from them.

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

    DOEpatents

    Deaton, Juan D [Menan, ID; Schmitt, Michael J [Idaho Falls, ID; Jones, Warren F [Idaho Falls, ID

    2011-12-13

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

  8. Container for radioactive materials

    DOEpatents

    Fields, Stanley R.

    1985-01-01

    A container for housing a plurality of canister assemblies containing radioactive material and disposed in a longitudinally spaced relation within a carrier to form a payload package concentrically mounted within the container. The payload package includes a spacer for each canister assembly, said spacer comprising a base member longitudinally spacing adjacent canister assemblies from each other and a sleeve surrounding the associated canister assembly for centering the same and conducting heat from the radioactive material in a desired flow path.

  9. Temporary Personal Radioactivity

    ERIC Educational Resources Information Center

    Myers, Fred

    2012-01-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

  10. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  11. Airborne field strength monitoring

    NASA Astrophysics Data System (ADS)

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

    2007-06-01

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

  12. Isolation and characterization of hot particles from Chernobyl fallout in southwestern Finland.

    PubMed

    Saari, H; Luokkanen, S; Kulmala, M; Lehtinen, S; Raunemaa, T

    1989-12-01

    Three types of activity composition have been found in airborne hot particles that were transported long distances from the Chernobyl accident. Their characterization is based on the analysis of single particles isolated from Pinus Sylvestris needles. The average activity of the particles was 130 Bq at the time of the accident. The most common type of particle contains the radioactive species 141Ce, 144Ce, 95Zr and 95Nb; the second type includes 103Ru and 106Ru along with the previous isotopes; and the third contains 103Ru and 106Ru only. Cesium-134 and -137 were present only in very small amounts. The activity composition of the Chernobyl reactor core fuel was similar to the composition of the first and second type particle; apparently the core fuel was only partially volatilized. The main bulk composition of the particles is shown to be U. The average aerodynamic size of the identified hot particles is 10 microns. The particles are rectangular or pentagonal in shape.

  13. Possibility of growth of airborne microbes in outer planetary atmospheres

    NASA Technical Reports Server (NTRS)

    Dimmick, R. L.; Chatigny, M. A.

    1975-01-01

    It is shown that airborne bacteria can maintain metabolic functions in a suitable atmosphere. It is theorized that particles in the Jovian atmosphere would have physical half-lives of 10 to 1500 years, depending upon which of two turbulent models is chosen.

  14. Lidar measurements of airborne particulate matter

    NASA Astrophysics Data System (ADS)

    Li, Guangkun; Philbrick, C. Russell

    2003-03-01

    Raman lidar techniques have been used in remote sensing to measure the aerosol optical extinction in the lower atmosphere, as well as water vapor, temperature and ozone profiles. Knowledge of aerosol optical properties assumes special importance in the wake of studies strongly correlating airborne particulate matter with adverse health effects. Optical extinction depends upon the concentration, composition, and size distribution of the particulate matter. Optical extinction from lidar returns provide information on particle size and density. The influence of relative humidity upon the growth and size of aerosols, particularly the sulfate aerosols along the northeast US region, has been investigated using a Raman lidar during several field measurement campaigns. A particle size distribution model is being developed and verified based on the experimental results. Optical extinction measurements from lidar in the NARSTO-NE-OPS program in Philadelphia PA, during summer of 1999 and 2001, have been analyzed and compared with other measurements such as PM sampling and particle size measurements.

  15. The influence of particle size distribution on dose conversion factors for radon progeny in the underground excavations of hard coal mine.

    PubMed

    Skubacz, Krystian; Wojtecki, Łukasz; Urban, Paweł

    2016-10-01

    In Polish underground mines, hazards caused by enhanced natural radioactivity occur. The sources of radiation exposure are short-lived radon decay products, mine waters containing radium (226)Ra and (228)Ra and the radioactive sediments that can precipitate out of these waters. For miners, the greatest exposure is usually due to short-lived radon decay products. The risk assessment is based on the measurement of the total potential alpha energy concentration (PAEC) and the evaluation of the related dose by using the dose conversion factor as recommended by relevant legal requirements. This paper presents the results of measurements of particle size distributions of ambient aerosols in an underground hard coal mine, the assessment of the radioactive particle size distribution of the short-lived radon decay products and the corresponding values of dose conversion factors. The measurements of the ambient airborne particle size distribution were performed in the range from a few nanometers to about 20 μm. The study therefore included practically the whole class of respirable particles. The results showed that the high concentration of ultrafine and fine aerosols measured can significantly affect the value of the dose conversion factors, and consequently the corresponding committed effective dose, to which the miners can be exposed.

  16. Airborne Submillimeter Spectroscopy

    NASA Technical Reports Server (NTRS)

    Zmuidzinas, J.

    1998-01-01

    This is the final technical report for NASA-Ames grant NAG2-1068 to Caltech, entitled "Airborne Submillimeter Spectroscopy", which extended over the period May 1, 1996 through January 31, 1998. The grant was funded by the NASA airborne astronomy program, during a period of time after the Kuiper Airborne Observatory was no longer operational. Instead. this funding program was intended to help develop instrument concepts and technology for the upcoming SOFIA (Stratospheric Observatory for Infrared Astronomy) project. SOFIA, which is funded by NASA and is now being carried out by a consortium lead by USRA (Universities Space Research Association), will be a 747 aircraft carrying a 2.5 meter diameter telescope. The purpose of our grant was to fund the ongoing development of sensitive heterodyne receivers for the submillimeter band (500-1200 GHz), using sensitive superconducting (SIS) detectors. In 1997 July we submitted a proposal to USRA to construct a heterodyne instrument for SOFIA. Our proposal was successful [1], and we are now continuing our airborne astronomy effort with funding from USRA. A secondary purpose of the NAG2-1068 grant was to continue the anaIN'sis of astronomical data collected with an earlier instrument which was flown on the NASA Kuiper Airborne Observatory (KAO). The KAO instrument and the astronomical studies which were carried out with it were supported primarily under another grant, NAG2-744, which extended over October 1, 1991 through Januarv 31, 1997. For a complete description of the astronomical data and its anailysis, we refer the reader to the final technical report for NAG2-744, which was submitted to NASA on December 1. 1997. Here we report on the SIS detector development effort for SOFIA carried out under NAG2-1068. The main result of this effort has been the demonstration of SIS mixers using a new superconducting material niobium titanium nitride (NbTiN), which promises to deliver dramatic improvements in sensitivity in the 700

  17. Airborne gamma-ray spectrometry in uranium exploration

    NASA Astrophysics Data System (ADS)

    Raghuwanshi, S. S.

    1992-07-01

    Uranium exploration is of paramount importance to India to maximize the indigeneous resources to meet the ever increasing demand for energy. Comprehensive regional and local zones of uranium mineralization are needed to be resolved. Such data comprise information on radioactivity in various energy ranges and on lithological knowledge. Airborne gamma-ray spectrometric techniques are particularly suited to provide spatial information. This review briefly discusses the conventional data presentation, statistically significant maps and the schemes suitable for classification of mineralized zones. A brief introduction is provided to airborne gamma-ray data, their acquisition, analysis, processing and interpretation to bring out their role in designing suitable models of uranium resources. State-of-the-art in uranium exploration covers radiometric mapping through airborne gamma-ray surveys. Through the examples of the Indian work done during this decade, the state-of-the-art and its usefulness in the country has been illustrated. It is concluded that the high sensitivity airborne gamma-ray spectrometric surveys coupled with modern methods of data analysis can further narrow down the targets.

  18. THE MORTALITY OF BACTERIOPHAGE CONTAINING ASSIMILATED RADIOACTIVE PHOSPHORUS

    PubMed Central

    Hershey, A. D.; Kamen, M. D.; Kennedy, J. W.; Gest, H.

    1951-01-01

    The bacteriophage T4 containing assimilated radioactive phosphorus is inactivated at a rate proportional to the specific radioactivity of the constituent phosphorus. The beta radiation from the phosphorus makes a negligible contribution to this effect. The inactivation is therefore a direct consequence of the nuclear reaction, which kills the phage with an efficiency of about 1/12. Several phages related to T4 behave similarly. When radioactive phage is grown from a seed of non-radioactive phage, all of the phage progeny are subject to killing by radioactive decay. The phage is killed by beta radiation from P32 with an efficiency of about 1/100 per ionization within the particle volume. Bacteriophage T4 and its relatives contain about 500,000 atoms of phosphorus per infective particle. Virtually all this phosphorus is adsorbed to bacteria with the specificity characteristic of the infective particles, and none of it can be removed from the particles by the enzyme desoxyribonuclease. The phosphorus content per particle, together with the published data on analytical composition, indicates a particle diameter close to 110 mµ for the varieties of phage studied. PMID:14824499

  19. Airborne myxomycete spores: detection using molecular techniques

    NASA Astrophysics Data System (ADS)

    Kamono, Akiko; Kojima, Hisaya; Matsumoto, Jun; Kawamura, Kimitaka; Fukui, Manabu

    2009-01-01

    Myxomycetes are organisms characterized by a life cycle that includes a fruiting body stage. Myxomycete fruiting bodies contain spores, and wind dispersal of the spores is considered important for this organism to colonize new areas. In this study, the presence of airborne myxomycetes and the temporal changes in the myxomycete composition of atmospheric particles (aerosols) were investigated with a polymerase chain reaction (PCR)-based method for Didymiaceae and Physaraceae. Twenty-one aerosol samples were collected on the roof of a three-story building located in Sapporo, Hokkaido Island, northern Japan. PCR analysis of DNA extracts from the aerosol samples indicated the presence of airborne myxomycetes in all the samples, except for the one collected during the snowfall season. Denaturing gradient gel electrophoresis (DGGE) analysis of the PCR products showed seasonally varying banding patterns. The detected DGGE bands were subjected to sequence analyses, and four out of nine obtained sequences were identical to those of fruiting body samples collected in Hokkaido Island. It appears that the difference in the fruiting period of each species was correlated with the seasonal changes in the myxomycete composition of the aerosols. Molecular evidence shows that newly formed spores are released and dispersed in the air, suggesting that wind-driven dispersal of spores is an important process in the life history of myxomycetes. This study is the first to detect airborne myxomycetes with the use of molecular ecological analyses and to characterize their seasonal distribution.

  20. Ultrafine Condensation Particle Counter Instrument Handbook

    SciTech Connect

    Kuang, C.

    2016-02-01

    The Model 3776 Ultrafine Condensation Particle Counter (UCPC; pictured in Appendix A) is designed for researchers interested in airborne particles smaller than 20 nm. With sensitivity to particles down to 2.5 nm in diameter, this UCPC is ideally suited for atmospheric and climate research, particle formation and growth studies, combustion and engine exhaust research, and nanotechnology research.

  1. The fate of airborne polycyclic organic matter.

    PubMed Central

    Nielsen, T; Ramdahl, T; Bjørseth, A

    1983-01-01

    Biological tests have shown that a significant part of the mutagenicity of organic extracts of collected airborne particulate matter is not due to polycyclic aromatic hydrocarbons (PAH). It is possible that part of these unknown compounds are transformation products of PAH. This survey focuses on the reaction of PAH in the atmosphere with other copollutants, such as nitrogen oxides, sulfur oxides, ozone and free radicals and their reaction products. Photochemically induced reactions of PAH are also included. The reactivity of particle-associated PAH is discussed in relation to the chemical composition and the physical properties of the carrier. Recommendations for future work are given. PMID:6825615

  2. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1991-01-01

    The systematics of induced radioactivity on the Long Duration Exposure Facility (LDEF) were studied in a wide range of materials using low level background facilities for detection of gamma rays. Approx. 400 samples of materials processed from structural parts of the spacecraft, as well as materials from onboard experiments, were analyzed at national facilities. These measurements show the variety of radioisotopes that are produced with half-lives greater than 2 wks, most of which are characteristic of proton induced reactions above 20 MeV. For the higher activity, long lived isotopes, it was possible to map the depth and directional dependences of the activity. Due to the stabilized configuration of the LDEF, the induced radioactivity data clearly show contributions from the anisotropic trapped proton flux in the South Atlantic Anomaly. This effect is discussed, along with evidence for activation by galactic protons and thermal neutrons. The discovery of Be-7 was made on leading side parts of the spacecraft, although this was though not to be related to the in situ production of radioisotopes from external particle fluxes.

  3. Radioactivity in the environment

    SciTech Connect

    Nagel, D.J.; Edson, R.

    1995-12-01

    Natural and man-made radioactivities in the environment have been extensively researched in the second half of this century. Recently, increased attention has been given to (1) radioactive waste willfully placed in the environment by discharges from nuclear reprocessing plants or by dumping at sea, and (2) radioactive materials lost due to accidents in terrestrial (civilian power) or marine (submarine propulsion) reactors. Increasing field measurements, and disclosures of dumping and accidents in the former Soviet Union, are adding greatly to the knowledge of environmental radioactivity. New, more powerful computers are having a double impact. They make possible Geographical Information Systems for geo-referencing and correlating multi-variable datasets. Furthermore, supercomputers enable global atmospheric, oceanographic and terrestrial circulation and transport models, which include physical, chemical and biological processes. We will review exemplary work on the sources, transport, disposition and impact of anthropogenic environmental radioactivity. Such work both provides new knowledge of environmental processes and furnishes the basis for deciding on potential remediation actions.

  4. Radioactivity in food crops

    SciTech Connect

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  5. Airborne Oceanographic Lidar System

    NASA Technical Reports Server (NTRS)

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

    1977-01-01

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

  6. Particle Deposition in a Child Respiratory Tract Model: In Vivo Regional Deposition of Fine and Ultrafine Aerosols in Baboons

    PubMed Central

    Albuquerque-Silva, Iolanda; Vecellio, Laurent; Durand, Marc; Avet, John; Le Pennec, Déborah; de Monte, Michèle; Montharu, Jérôme; Diot, Patrice; Cottier, Michèle; Dubois, Francis; Pourchez, Jérémie

    2014-01-01

    To relate exposure to adverse health effects, it is necessary to know where particles in the submicron range deposit in the respiratory tract. The possibly higher vulnerability of children requires specific inhalation studies. However, radio-aerosol deposition experiments involving children are rare because of ethical restrictions related to radiation exposure. Thus, an in vivo study was conducted using three baboons as a child respiratory tract model to assess regional deposition patterns (thoracic region vs. extrathoracic region) of radioactive polydisperse aerosols ([d16–d84], equal to [0.15 µm–0.5 µm], [0.25 µm–1 µm], or [1 µm–9 µm]). Results clearly demonstrated that aerosol deposition within the thoracic region and the extrathoraic region varied substantially according to particle size. High deposition in the extrathoracic region was observed for the [1 µm–9 µm] aerosol (72%±17%). The [0.15 µm–0.5 µm] aerosol was associated almost exclusively with thoracic region deposition (84%±4%). Airborne particles in the range of [0.25 µm–1 µm] showed an intermediate deposition pattern, with 49%±8% in the extrathoracic region and 51%±8% in the thoracic region. Finally, comparison of baboon and human inhalation experiments for the [1 µm–9 µm] aerosol showed similar regional deposition, leading to the conclusion that regional deposition is species-independent for this airborne particle sizes. PMID:24787744

  7. Particle deposition in a child respiratory tract model: in vivo regional deposition of fine and ultrafine aerosols in baboons.

    PubMed

    Albuquerque-Silva, Iolanda; Vecellio, Laurent; Durand, Marc; Avet, John; Le Pennec, Déborah; de Monte, Michèle; Montharu, Jérôme; Diot, Patrice; Cottier, Michèle; Dubois, Francis; Pourchez, Jérémie

    2014-01-01

    To relate exposure to adverse health effects, it is necessary to know where particles in the submicron range deposit in the respiratory tract. The possibly higher vulnerability of children requires specific inhalation studies. However, radio-aerosol deposition experiments involving children are rare because of ethical restrictions related to radiation exposure. Thus, an in vivo study was conducted using three baboons as a child respiratory tract model to assess regional deposition patterns (thoracic region vs. extrathoracic region) of radioactive polydisperse aerosols ([d16-d84], equal to [0.15 µm-0.5 µm], [0.25 µm-1 µm], or [1 µm-9 µm]). Results clearly demonstrated that aerosol deposition within the thoracic region and the extrathoraic region varied substantially according to particle size. High deposition in the extrathoracic region was observed for the [1 µm-9 µm] aerosol (72% ± 17%). The [0.15 µm-0.5 µm] aerosol was associated almost exclusively with thoracic region deposition (84% ± 4%). Airborne particles in the range of [0.25 µm-1 µm] showed an intermediate deposition pattern, with 49% ± 8% in the extrathoracic region and 51% ± 8% in the thoracic region. Finally, comparison of baboon and human inhalation experiments for the [1 µm-9 µm] aerosol showed similar regional deposition, leading to the conclusion that regional deposition is species-independent for this airborne particle sizes.

  8. Airborne concentrations of peanut protein.

    PubMed

    Johnson, Rodney M; Barnes, Charles S

    2013-01-01

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

  9. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  10. Radioactivity of Consumer Products

    NASA Astrophysics Data System (ADS)

    Peterson, David; Jokisch, Derek; Fulmer, Philip

    2006-11-01

    A variety of consumer products and household items contain varying amounts of radioactivity. Examples of these items include: FiestaWare and similar glazed china, salt substitute, bananas, brazil nuts, lantern mantles, smoke detectors and depression glass. Many of these items contain natural sources of radioactivity such as Uranium, Thorium, Radium and Potassium. A few contain man-made sources like Americium. This presentation will detail the sources and relative radioactivity of these items (including demonstrations). Further, measurements of the isotopic ratios of Uranium-235 and Uranium-238 in several pieces of china will be compared to historical uses of natural and depleted Uranium. Finally, the presenters will discuss radiation safety as it pertains to the use of these items.

  11. Container for radioactive materials

    DOEpatents

    Fields, S.R.

    1984-05-30

    A container is claimed for housing a plurality of canister assemblies containing radioactive material. The several canister assemblies are stacked in a longitudinally spaced relation within a carrier to form a payload concentrically mounted within the container. The payload package includes a spacer for each canister assembly, said spacer comprising a base member longitudinally spacing adjacent canister assemblies from each other and sleeve surrounding the associated canister assembly for centering the same and conducting heat from the radioactive material in a desired flow path. 7 figures.

  12. Background X-ray Spectrum of Radioactive Samples

    SciTech Connect

    Shannon Yee; Dawn E. Janney

    2008-02-01

    An energy-dispersive X-ray spectrometer (EDS) is commonly used with a scanning electron microscope (SEM) to analyze the elemental compositions and microstructures of a variety of samples. For example, the microstructures of nuclear fuels are commonly investigated with this technique. However, the radioactivity of some materials introduces additional X-rays that contribute to the EDS background spectrum. These X-rays are generally not accounted for in spectral analysis software, and can cause misleading results. X-rays from internal conversion [1], Bremsstrahlung [2] radiation associated with alpha ionizations and beta particle interactions [3], and gamma rays from radioactive decay can all elevate the background of radioactive materials.

  13. The New Airborne Disease

    PubMed Central

    Goldsmith, John R.

    1970-01-01

    Community air pollution is the new airborne disease of our generation's communities. It is caused by the increasing use of fuel, associated with both affluence and careless waste. Photochemical air pollution of the California type involves newly defined atmospheric reactions, is due mostly to motor vehicle exhaust, is oxidizing, and produces ozone, plant damage, impairment of visibility and eye and respiratory symptoms. Aggravation of asthma, impairment of lung function among persons with chronic respiratory disease and a possible causal role, along with cigarette smoking in emphysema and chronic bronchitis, are some of the effects of photochemical pollution. More subtle effects of pollution include impairment of oxygen transport by the blood due to carbon monoxide and interference with porphyrin metabolism due to lead. Carbon monoxide exposures may affect survival of patients who are in hospitals because of myocardial infarction. While many uncertainties in pollution-health reactions need to be resolved, a large number of people in California have health impairment due to airborne disease of this new type. PMID:5485227

  14. Monitor for detecting and assessing exposure to airborne nanoparticles

    NASA Astrophysics Data System (ADS)

    Marra, Johan; Voetz, Matthias; Kiesling, Heinz-Jürgen

    2010-01-01

    An important safety aspect of the workplace environment concerns the severity of its air pollution with nanoparticles (NP; <100 nm) and ultrafine particles (UFP; <300 nm). Depending on their size and chemical nature, exposure to these particles through inhalation can be hazardous because of their intrinsic ability to deposit in the deep lung regions and the possibility to subsequently pass into the blood stream. Recommended safety measures in the nanomaterials industry are pragmatic, aiming at exposure minimization in general, and advocating continuous control by monitoring both the workplace air pollution level and the personal exposure to airborne NPs. This article describes the design and operation of the Aerasense NP monitor that enables intelligence gathering in particular with respect to airborne particles in the 10-300 nm size range. The NP monitor provides real time information about their number concentration, average size, and surface areas per unit volume of inhaled air that deposit in the various compartments of the respiratory tract. The monitor's functionality relies on electrical charging of airborne particles and subsequent measurements of the total particle charge concentration under various conditions. Information obtained with the NP monitor in a typical workplace environment has been compared with simultaneously recorded data from a Scanning Mobility Particle Sizer (SMPS) capable of measuring the particle size distribution in the 11-1086 nm size range. When the toxicological properties of the engineered and/or released particles in the workplace are known, personal exposure monitoring allows a risk assessment to be made for a worker during each workday, when the workplace-produced particles can be distinguished from other (ambient) particles.

  15. MULTIPLY: Development of a European HSRL Airborne Facility

    NASA Astrophysics Data System (ADS)

    Binietoglou, Ioannis; Serikov, Ilya; Nicolae, Doina; Amiridis, Vassillis; Belegante, Livio; Boscornea, Andrea; Brugmann, Bjorn; Costa Suros, Montserrat; Hellmann, David; Kokkalis, Panagiotis; Linne, Holger; Stachlewska, Iwona; Vajaiac, Sorin-Nicolae

    2016-08-01

    MULTIPLY is a novel airborne high spectral resolution lidar (HSRL) currently under development by a consortium of European institutions from Romania, Germany, Greece, and Poland. Its aim is to contribute to calibration and validations activities of the upcoming ESA aerosol sensing missions like ADM-Aeolus, EarthCARE and the Sentinel-3/-4/-5/-5p which include products related to atmospheric aerosols. The effectiveness of these missions depends on independent airborne measurements to develop and test the retrieval methods, and validate mission products following launch. The aim of ESA's MULTIPLY project is to design, develop, and test a multi-wavelength depolarization HSRL for airborne applications. The MULTIPLY lidar will deliver the aerosol extinction and backscatter coefficient profiles at three wavelengths (355nm, 532nm, 1064nm), as well as profiles of aerosol intensive parameters (Ångström exponents, extinction- to-backscatter ratios, and linear particle depolarization ratios).

  16. FINE PARTICLES ARE MORE STRONGLY ASSOCIATED THAN COARSE PARTICLES WITH ACUTE REPIRATORY HEALTH EFFECTS IN SCHOOL CHILDREN

    EPA Science Inventory

    Numerous studies have reported associations between airborne particles and a range of respiratory outcomes from symptoms to mortality. Current attention has been focused on the characteristics of these particles responsible for the adverse health effects. We have reanalyzed three...

  17. Airborne Dust in Space Vehicles and Habitats

    NASA Technical Reports Server (NTRS)

    James, John

    2006-01-01

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

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

    PubMed

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

    2012-03-01

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

  19. Characterization of Airborne Bacteria at an Underground Subway Station

    PubMed Central

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

    2012-01-01

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

  20. Respiratory protection against airborne nanoparticles: a review

    NASA Astrophysics Data System (ADS)

    Shaffer, Ronald E.; Rengasamy, Samy

    2009-10-01

    As a precautionary measure, it is often recommended that workers take steps to reduce their exposure to airborne nanoparticles through the use of respiratory protective devices. The purpose of this study was to provide a review and analysis of the research literature and current recommendations on respirators used for protection against nanoparticles. Key research findings were that studies with particles as small as 4 nm have shown that conventional single-fiber filtration theory can be used to describe the filtration performance of respirators and that the most penetrating particle size for respirators equipped with commonly used electrostatic filter media is in the range of 30-100 nm. Future research needs include human laboratory and workplace protection factor studies to measure the respirator total inward leakage of nanoparticles. Industrial hygienists and safety professionals should continue to use traditional respirator selection guidance for workers exposed to nanoparticles.

  1. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  2. Detecting Illicit Radioactive Sources

    SciTech Connect

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  3. TABLE OF RADIOACTIVE ELEMENTS.

    SciTech Connect

    HOLDEN,N.E.

    2001-06-29

    For those chemical elements which have no stable nuclides with a terrestrial isotopic composition, the data on radioactive half-lives and relative atomic masses for the nuclides of interest and importance have been evaluated and the recommended values and uncertainties are listed.

  4. AIR RADIOACTIVITY MONITOR

    DOEpatents

    Bradshaw, R.L.; Thomas, J.W.

    1961-04-11

    The monitor is designed to minimize undesirable background buildup. It consists of an elongated column containing peripheral electrodes in a central portion of the column, and conduits directing an axial flow of radioactively contaminated air through the center of the column and pure air through the annular portion of the column about the electrodes. (AEC)

  5. Radioactivity: A Natural Phenomenon.

    ERIC Educational Resources Information Center

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  6. Viewer Makes Radioactivity "Visible"

    NASA Technical Reports Server (NTRS)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  7. Radioactivity and foods

    SciTech Connect

    Olszyna-Marzys, A.E. )

    1991-01-01

    The purpose of this article is to describe and contrast two relationships between radiation and food--on the one hand, beneficial preservation of food by controlled exposure to ionizing radiation; and, on the other, contamination of food by accidental incorporation of radioactive nuclides within the food itself. In food irradiation, electrons or electromagnetic radiation is used to destroy microorganisms and insects or prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undersirable changes or induced radioactivity is produced in the irradiated food. An altogether different situation is presented by exposure of food animals and farming areas to radioactive materials, as occurred after the major Soviet nuclear reactor accident at Chenobyl. This article furnishes the basic information needed to understand the nature of food contamination associated with that event and describes the work of international organizations seeking to establish appropriate safe limits for levels of radioactivity in foods.

  8. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  9. Processor architecture for airborne SAR systems

    NASA Technical Reports Server (NTRS)

    Glass, C. M.

    1983-01-01

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

  10. Evaluation of meteorological airborne Doppler radar

    NASA Technical Reports Server (NTRS)

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

    1984-01-01

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

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

    PubMed

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

    2015-05-26

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

  12. Characteristics of airborne bacteria in Mumbai urban environment.

    PubMed

    Gangamma, S

    2014-08-01

    Components of biological origin constitute small but a significant proportion of the ambient airborne particulate matter (PM). However, their diversity and role in proinflammatory responses of PM are not well understood. The present study characterizes airborne bacterial species diversity in Mumbai City and elucidates the role of bacterial endotoxin in PM induced proinflammatory response in ex vivo. Airborne bacteria and endotoxin samples were collected during April-May 2010 in Mumbai using six stage microbial impactor and biosampler. The culturable bacterial species concentration was measured and factors influencing the composition were identified by principal component analysis (PCA). The biosampler samples were used to stimulate immune cells in whole blood assay. A total of 28 species belonging to 17 genera were identified. Gram positive and spore forming groups of bacteria dominated the airborne culturable bacterial concentration. The study indicated the dominance of spore forming and human or animal flora derived pathogenic/opportunistic bacteria in the ambient air environment. Pathogenic and opportunistic species of bacteria were also present in the samples. TNF-α induction by PM was reduced (35%) by polymyxin B pretreatment and this result was corroborated with the results of blocking endotoxin receptor cluster differentiation (CD14). The study highlights the importance of airborne biological particles and suggests need of further studies on biological characterization of ambient PM.

  13. Method for calcining radioactive wastes

    DOEpatents

    Bjorklund, William J.; McElroy, Jack L.; Mendel, John E.

    1979-01-01

    This invention relates to a method for the preparation of radioactive wastes in a low leachability form by calcining the radioactive waste on a fluidized bed of glass frit, removing the calcined waste to melter to form a homogeneous melt of the glass and the calcined waste, and then solidifying the melt to encapsulate the radioactive calcine in a glass matrix.

  14. AIRBORNE RADIATION DETECTOR

    DOEpatents

    Cartmell, T.R.; Gifford, J.F.

    1959-08-01

    An ionization chamber used for measuring the radioactivity of dust present in atmospheric air is described. More particularly. the patent describes a device comprising two concentric open ended, electrically connected cylinders between which is disposed a wire electrcde. A heating source is disposed inside of the cylinder to circulate air through the space between the two cylinders by convective flow. A high voltage electric field between the wire electrcde of the electrically connected cylinder will cause ionization of the air as it passes therethrough.

  15. The Discovery of Artificial Radioactivity

    NASA Astrophysics Data System (ADS)

    Guerra, Francesco; Leone, Matteo; Robotti, Nadia

    2012-03-01

    We reconstruct Frédéric Joliot and Irène Curie's discovery of artificial radioactivity in January 1934 based in part on documents preserved in the Joliot-Curie Archives in Paris, France. We argue that their discovery followed from the convergence of two parallel lines of research, on the neutron and on the positron, that were focused on a well-defined experimental problem, the nuclear transmutation of aluminum and other light elements. We suggest that a key role was played by a suggestion that Francis Perrin made at the seventh Solvay Conference at the end of October 1933, that the alpha-particle bombardment of aluminum produces an intermediate unstable isotope of phosphorus, which then decays by positron emission. We also suggest that a further idea that Perrin published in December 1933, and the pioneering theory of beta decay that Enrico Fermi also first published in December 1933, established a new theoretical framework that stimulated Joliot to resume the researches that he and Curie had interrupted after the Solvay Conference, now for the first time using a Geiger-Müller counter to detect the positrons emitted when he bombarded aluminum with polonium alpha particles.

  16. Proof-of-principle results for identifying the composition of dust particles and volcanic ash samples through the technique of photon activation analysis at the IAC

    NASA Astrophysics Data System (ADS)

    Mamtimin, Mayir; Cole, Philip L.; Segebade, Christian

    2013-04-01

    Instrumental analytical methods are preferable in studying sub-milligram quantities of airborne particulates collected in dust filters. The multi-step analytical procedure used in treating samples through chemical separation can be quite complicated. Further, due to the minute masses of the airborne particulates collected on filters, such chemical treatment can easily lead to significant levels of contamination. Radio-analytical techniques, and in particular, activation analysis methods offer a far cleaner alternative. Activation methods require minimal sample preparation and provide sufficient sensitivity for detecting the vast majority of the elements throughout the periodic table. In this paper, we will give a general overview of the technique of photon activation analysis. We will show that by activating dust particles with 10- to 30-MeV bremsstrahlung photons, we can ascertain their elemental composition. The samples are embedded in dust-collection filters and are irradiated "as is" by these photons. The radioactivity of the photonuclear reaction products is measured with appropriate spectrometers and the respective analytes are quantified using multi-component calibration materials. We shall provide specific examples of identifying the elemental components of airborne dust particles and volcanic ash by making use of bremsstrahlung photons from an electron linear accelerator at the Idaho Accelerator Center in Pocatello, Idaho.

  17. Airborne Cloud Computing Environment (ACCE)

    NASA Technical Reports Server (NTRS)

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

    2011-01-01

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

  18. Airborne agent concentration analysis

    DOEpatents

    Gelbard, Fred

    2004-02-03

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

  19. Airborne Wind Turbine

    SciTech Connect

    2010-09-01

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

  20. Column Closure Studies of Lower Tropospheric Aerosol and Water Vapor During ACE-Asia Using Airborne Sunphotometer, Airborne In-Situ and Ship-Based Lidar Measurements

    NASA Technical Reports Server (NTRS)

    Schmid, B.; Hegg, A.; Wang, J.; Bates, D.; Redemann, J.; Russells, P. B.; Livingston, J. M.; Jonsson, H. H.; Welton, E. J.; Seinfield, J. H.

    2003-01-01

    We assess the consistency (closure) between solar beam attenuation by aerosols and water vapor measured by airborne sunphotometry and derived from airborne in-situ, and ship-based lidar measurements during the April 2001 Asian Pacific Regional Aerosol Characterization Experiment (ACE-Asia). The airborne data presented here were obtained aboard the Twin Otter aircraft. Comparing aerosol extinction o(550 nm) from four different techniques shows good agreement for the vertical distribution of aerosol layers. However, the level of agreement in absolute magnitude of the derived aerosol extinction varied among the aerosol layers sampled. The sigma(550 nm) computed from airborne in-situ size distribution and composition measurements shows good agreement with airborne sunphotometry in the marine boundary layer but is considerably lower in layers dominated by dust if the particles are assumed to be spherical. The sigma(550 nm) from airborne in-situ scattering and absorption measurements are about approx. 13% lower than those obtained from airborne sunphotometry during 14 vertical profiles. Combining lidar and the airborne sunphotometer measurements reveals the prevalence of dust layers at altitudes up to 10 km with layer aerosol optical depth (from 3.5 to 10 km altitude) of approx. 0.1 to 0.2 (500 nm) and extinction-to-backscatter ratios of 59-71 sr (523 nm). The airborne sunphotometer aboard the Twin Otter reveals a relatively dry atmosphere during ACE- Asia with all water vapor columns less than 1.5 cm and water vapor densities w less than 12 g/cu m. Comparing layer water vapor amounts and w from the airborne sunphotometer to the same quantities measured with aircraft in-situ sensors leads to a high correlation (r(sup 3)=0.96) but the sunphotometer tends to underestimate w by 7%.

  1. Airborne particulate discriminator

    DOEpatents

    Creek, Kathryn Louise; Castro, Alonso; Gray, Perry Clayton

    2009-08-11

    A method and apparatus for rapid and accurate detection and discrimination of biological, radiological, and chemical particles in air. A suspect aerosol of the target particulates is treated with a taggant aerosol of ultrafine particulates. Coagulation of the taggant and target particles causes a change in fluorescent properties of the cloud, providing an indication of the presence of the target.

  2. Airborne Geophysical Surveys Applied to Hydrocarbon Resource Development Environmental Studies

    NASA Astrophysics Data System (ADS)

    Smith, B. D.; Ball, L. B.; Finn, C.; Kass, A.; Thamke, J.

    2014-12-01

    mapping AEM surveys could also be effectively used in mapping tectonic features. Airborne radiometric methods have not been routinely used in hydrocarbon environmental studies but might be useful in understanding the surficial distribution of deposits related to naturally occurring radioactive materials.

  3. International radioactive material recycling challenges

    SciTech Connect

    Greeves, John T.; Lieberman, James

    2007-07-01

    The paper explores current examples of successful International radioactive recycling programs and also explores operational regulatory and political challenges that need to be considered for expanding international recycling world-wide. Most countries regulations are fully consistent with the International Atomic Agency (IAEA) Code of Practice on the International Transboundary Movement of Radioactive Material and the IAEA Code of Conduct on the Safety and Security of Radioactive Sources. IAEA member States reported on the status of their efforts to control transboundary movement of radioactive material recently during the Joint Convention on the Safety of Spent Fuel management and on the Safety of Radioactive Waste Management meeting in May 2006. (authors)

  4. [Studies on the size distribution of airborne microbes at home in Beijing].

    PubMed

    Fang, Zhi-Guo; Sun, Ping; Ouyang, Zhi-Yun; Liu, Peng; Sun, Li; Wang, Xiao-Yong

    2013-07-01

    The effect of airborne microbes on human health not only depends on their compositions (genera and species), but also on their concentrations and sizes. Moreover, there are different mechanisms of airborne microbes of different sizes with different effects on human health. The size distributions and median diameters were investigated in detail with imitated six-stage Andersen sampler in 31 selected family homes with children in Beijing. Results showed that there was similar distribution characteristics of airborne microbes in different home environment, different season, different child's sex, and different apartment's architecture, but different distribution characteristics between airborne bacteria and fungi were observed in family homes in Beijing. In general, although airborne bacteria and fungi were plotted with normal logarithmic distribution, the particle percentage of airborne bacteria increased gradually from stage 1 (> 8.2 microm) to stage 5 (1.0-2.0 microm), and then decreased dramatically in stage 6 (< 1.0 microm), the percentage of airborne fungi increased gradually from stage 1 to stage 4 (2.0-3.5 microm), and then decreased dramatically from stage 4 to stage 6. The size distributions of dominant fungi were different in different fungal genera. Cladosporium, Penicillium and Aspergillus were recorded with normal logarithmic distribution, with the highest percentage detected in stage 4, and Alternaria were observed with skew distribution, with the highest percentage detected in stage 2 (5.0-10.4 microm). Finally, the median diameters of airborne bacteria were larger than those of airborne fungi, and the lowest median diameter of airborne bacteria and fungi was found in winter, while there were no significant variations of airborne bacterial and fungal median diameters in spring, summer and autumn in a year in this study.

  5. Exposure to mineral sands dust particles

    NASA Astrophysics Data System (ADS)

    Dias da Cunha, K.; Barros Leite, C. V.; Zays, Z.

    2004-06-01

    The aim of this study is to characterize the airborne particles in a Brazilian region with high concentration of mineral sands (Buena village). In this study proton induced X-ray emission (PIXE), plasma desorption mass spectrometry and alpha spectrometry were used for analyses of airborne particles. The analyses of aerosol samples and lichen samples show that the inhabitants of the Buena village are exposed to airborne particles in the fine fraction of aerosols. The main anthropogenic sources of particles are the mineral sands processing plant and truck traffic, and natural sources as the sea, soil and the swamp. The results from the lichen samples show that at least during the last 15 years the inhabitants of the village have been exposed to monazite particles. The results from aerosols and lichens samples also suggested that the swamp is a source of 226Ra and 210Pb bearing particles besides the monazite dust.

  6. PROCESSING OF RADIOACTIVE WASTE

    DOEpatents

    Johnson, B.M. Jr.; Barton, G.B.

    1961-11-14

    A process for treating radioactive waste solutions prior to disposal is described. A water-soluble phosphate, borate, and/or silicate is added. The solution is sprayed with steam into a space heated from 325 to 400 deg C whereby a powder is formed. The powder is melted and calcined at from 800 to 1000 deg C. Water vapor and gaseous products are separated from the glass formed. (AEC)

  7. Table of radioactive elements

    SciTech Connect

    Holden, N.E.

    1985-01-01

    As has been the custom in the past, the Commission publishes a table of relative atomic masses and halflives of selected radionuclides. The information contained in this table will enable the user to calculate the atomic weight for radioactive materials with a variety of isotopic compositions. The atomic masses have been taken from the 1984 Atomic Mass Table. Some of the halflives have already been documented.

  8. MARE: Mars Radioactivity Experiment

    NASA Astrophysics Data System (ADS)

    di Lellis, A. M.; Capria, M. T.; Espinasse, S.; Magni, G.; Orosei, R.; Piccioni, G.; Federico, C.; Minelli, G.; Pauselli, C.; Scarpa, G.

    1999-09-01

    MARE is an experiment for the measurement of the beta and gamma radioactivity in space and in the Martian soil, both at the surface and in the subsurface. This will be accomplished by means of a dosimeter and a spectrometer. The radiation dose rate to which crews will be exposed is one of the hazards that has to be quantified before the human exploration of Mars may begin. Data for evaluating radioactivity levels at Martian surface are of great interest for environmental studies related to life in general. The dosimeter will be able to measure the beta and gamma radiation dose received, with a responsivity which is very close to that of a living organism. The dosimeter is based on thermo-luminescence pills which emit an optical signal proportional to the absorbed dose when heated. Radioactive elements ((40) K, (235) U, (238) U and (232) Th) can be used as a mean of tracing the evolution of a terrestrial planet. These radioactive elements are the source of the internal heat, which drives convection in the mantle. They have been redistributed in this process and they are now concentrated in the crust where they are accessible for study. Their different behavior during the fractionation process can be used as a mean to investigate the geochemical characteristic of Mars. The spectrometer, a scintillation radiation absorber system for single event counting, is capable of detecting gamma photons with energies between 200 KeV and 10 MeV. The detected events will be processed in such a way to allow the recognition of the spectral signature of different decay processes, and thus the identification and the measurement of the concentrations of different radionuclides in the Martian soil.

  9. Temporal change in the size distribution of airborne Radiocesium derived from the Fukushima accident

    NASA Astrophysics Data System (ADS)

    Kaneyasu, Naoki; Ohashi, Hideo; Suzuki, Fumie; Okuda, Tomoaki; Ikemori, Fumikazu; Akata, Naofumi

    2013-04-01

    The accident of Fukushima Dai-ichi nuclear power plant discharged a large amount of radioactive materials into the environment. After 40 days of the accident, we started to collect the size-segregated aerosol at Tsukuba City, Japan, located 170 km south of the plant, by use of a low-pressure cascade impactor. The sampling continued from April 28, through October 26, 2011. The number of sample sets collected in total was 8. The radioactivity of 134Cs and 137Cs in aerosols collected at each stage were determined by gamma-ray with a high sensitivity Germanic detector. After the gamma-ray spectrometry analysis, the chemical species in the aerosols were analyzed. The analyses of first (April 28-May 12) and second (May 12-26) samples showed that the activity size distributions of 134Cs and 137Cs in aerosols reside mostly in the accumulation mode size range. These activity size distributions almost overlapped with the mass size distribution of non-sea-salt sulfate aerosol. From the results, we regarded that sulfate is the main transport medium of these radionuclides, and re-suspended soil particles that attached radionuclides were not the major airborne radioactive substances by the end of May, 2011 (Kaneyasu et al., 2012). We further conducted the successive extraction experiment of radiocesium from the aerosol deposits on the aluminum sheet substrate (8th stage of the first aerosol sample, 0.5-0.7 μm in aerodynamic diameter) with water and 0.1M HCl. In contrast to the relatively insoluble property of Chernobyl radionuclides, those in aerosols collected at Tsukuba in fine mode are completely water-soluble (100%). From the third aerosol sample, the activity size distributions started to change, i.e., the major peak in the accumulation mode size range seen in the first and second aerosol samples became smaller and an additional peak appeared in the coarse mode size range. The comparison of the activity size distributions of radiocesium and the mass size distributions of

  10. Experiences managing radioactive material at the National Ignition Facility.

    PubMed

    Thacker, Rick L

    2013-06-01

    The National Ignition Facility at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion and experiments studying high energy density science. Many experiments performed at the National Ignition Facility involve radioactive materials; these may take the form of tritium and small quantities of depleted uranium used in targets, activation products created by neutron-producing fusion experiments, and fission products produced by the fast fissioning of the depleted uranium. While planning for the introduction of radioactive material, it was recognized that some of the standard institutional processes would need to be customized to accommodate aspects of NIF operations, such as surface contamination limits, radiological postings, airborne tritium monitoring protocols, and personnel protective equipment. These customizations were overlaid onto existing work practices to accommodate the new hazard of radioactive materials. This paper will discuss preparations that were made prior to the introduction of radioactive material, the types of radiological work activities performed, and the hazards and controls encountered. Updates to processes based on actual monitoring results are also discussed.

  11. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, R.D.; McPheeters, C.C.

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  12. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, Raymond D.; McPheeters, Charles C.

    1980-01-01

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  13. Radioactive waste storage issues

    SciTech Connect

    Kunz, Daniel E.

    1994-08-15

    In the United States we generate greater than 500 million tons of toxic waste per year which pose a threat to human health and the environment. Some of the most toxic of these wastes are those that are radioactively contaminated. This thesis explores the need for permanent disposal facilities to isolate radioactive waste materials that are being stored temporarily, and therefore potentially unsafely, at generating facilities. Because of current controversies involving the interstate transfer of toxic waste, more states are restricting the flow of wastes into - their borders with the resultant outcome of requiring the management (storage and disposal) of wastes generated solely within a state`s boundary to remain there. The purpose of this project is to study nuclear waste storage issues and public perceptions of this important matter. Temporary storage at generating facilities is a cause for safety concerns and underscores, the need for the opening of permanent disposal sites. Political controversies and public concern are forcing states to look within their own borders to find solutions to this difficult problem. Permanent disposal or retrievable storage for radioactive waste may become a necessity in the near future in Colorado. Suitable areas that could support - a nuclear storage/disposal site need to be explored to make certain the health, safety and environment of our citizens now, and that of future generations, will be protected.

  14. Radioactive deposits of Nevada

    USGS Publications Warehouse

    Lovering, T.G.

    1954-01-01

    Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by personnel of the U. S. Geological Surveyor of the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified at 13 sites; two sites contained a thorium mineral (monazite); the source of radioactivity on nine properties was not ascertained, and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and nine are placers containing thorian monazite. Pitchblende occurs at two localities, the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontite. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint, only four of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951; the Majuba Hill mine; the Stalin's Present prospect; and the West Willys claim in the Washington district. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

  15. Radioactive deposits of Nevada

    USGS Publications Warehouse

    Lovering, T.G.

    1953-01-01

    Thirty-five occurrences of radioactive rocks had been reported from Nevada prior to 1952. Twenty-five of these had been investigated by the U. S. Geological Survey and the U. S. Atomic Energy Commission. Of those investigated, uranium minerals were identified in 13; two contained a thorium mineral (monazite); the source of radioactivity on 7 properties was not ascertained; and one showed no abnormal radioactivity. Of the other reported occurrences, one is said to contain uraniferous hydrocarbons and 9 are placers containing thorian monazite. Pitchblende occurs at two localities; the East Walker River area, and the Stalin's Present prospect, where it is sparsely disseminated in tabular bodies cutting granitic rocks. Other uranium minerals found in the state include: carnotite, tyuyamunite, autunite, torbernite, gummite, uranophane, kasolite, and an unidentified mineral which may be dumontit. Monazite is the only thorium mineral of possible economic importance that has been reported. From an economic standpoint 9 only 4 of the properties examined showed reserves of uranium ore in 1952; these are: the Green Monster mine, which shipped 5 tons of ore to Marysvale, Utah, during 1951, the Majuba Hill mine, the Stalin's Present prospect, and the West Willys claim in the Washington district. Reserves of ore grade are small on all of these properties and probably cannot be developed commercially unless an ore-buying station is set up nearby. No estimate has been made of thorium reserves and no commercial deposits of thorium are known.

  16. Measurement of airborne {sup 218}Po - A Bayesian approach

    SciTech Connect

    Groer, P.G.; Lo, Y.

    1996-12-01

    The standard mathematical treatment of the buildup and decay of airborne radionuclides on a filter paper uses the solutions of the so-called bateman equations adapted to the sampling process. The equations can be interpreted as differential equations for the expectation of an underlying stochastic process, which describes the random fluctuations in the accumulation and decay of the sampled radioactive atoms. The process for the buildup and decay of airborne {sup 218}Po can be characterized as an {open_quotes}immigration-death process{close_quotes} in the widely adopted, biologically based jargon. The probability distribution for the number of {sup 218}Po atoms, accumulated after sampling time t, is Poisson. We show that the distribution of the number of counts, registered by a detector with efficiency {epsilon} during a counting period T after the end of sampling, it also Poisson, with mean dependent on {epsilon},t,T, the flowrate and N{sub o}, the number of airborne {sup 218}Po atoms per unit volume. This Poisson distribution was used to construct the likelihood given the observed number of counts. After inversion with Bayes` Theorem we obtained the posterior density for N{sub o}. This density characterizes the remaining uncertainty about the measured under of {sup 218}Po atoms per unit volume of air. 6 refs., 3 figs., 1 tab.

  17. Manufactured and Airborne Nanoparticle Cardiopulmonary Interactions: A Review of Mechanisms and the Possible Contribution of Mast Cells

    EPA Science Inventory

    Human inhalation exposures to manufactured nanoparticles (NP) and airborne ultrafine particles (UFP) continues to increase in both occupational and environmental settings. UFP exposures have been associated with increased cardiovascular mortality and morbidity, while ongoing res...

  18. System for measuring radioactivity of labelled biopolymers

    SciTech Connect

    Gross, V.

    1980-07-08

    A system is described for measuring radioactivity of labelled biopolymers, comprising: a set of containers adapted for receiving aqueous solutions of biological samples containing biopolymers which are subsequently precipitated in said containers on particles of diatomite in the presence of a coprecipitator, then filtered, dissolved, and mixed with a scintillator; radioactivity measuring means including a detection chamber to which is fed the mixture produced in said set of containers; an electric drive for moving said set of containers in a stepwise manner; means for proportional feeding of said coprecipitator and a suspension of diatomite in an acid solution to said containers which contain the biological sample for forming an acid precipitation of biopolymers; means for the removal of precipitated samples from said containers; precipitated biopolymer filtering means for successively filtering the precipitate, suspending the precipitate, dissolving the biopolymers mixed with said scintillator for feeding of the mixture to said detection chamber; a system of pipelines interconnecting said above-recited means; and said means for measuring radioactivity of labelled biopolymers including, a measuring cell arranged in a detection chamber and communicating with said means for filtering precipitated biopolymers through one pipeline of said system of pipelines; a program unit electrically connected to said electric drive, said means for acid precipatation of biopolymers, said means for the removal of precipitated samples from said containers, said filtering means, and said radioactivity measuring device; said program unit adapted to periodically switch on and off the above-recited means and check the sequence of the radioactivity measuring operations; and a control unit for controlling the initiation of the system and for selecting programs.

  19. The development of radioactive sample surrogates for training and exercises

    SciTech Connect

    Martha Finck; Bevin Brush; Dick Jansen; David Chamberlain; Don Dry; George Brooks; Margaret Goldberg

    2012-03-01

    The development of radioactive sample surrogates for training and exercises Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a Radioactive Response Training Range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Members from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive Br-82 isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.

  20. Characterization of airborne and bulk particulate from iron and steel manufacturing facilities.

    PubMed

    Machemer, Steven D

    2004-01-15

    Characterization of airborne and bulk particulate material from iron and steel manufacturing facilities, commonly referred to as kish, indicated graphite flakes and graphite flakes associated with spherical iron oxide particles were unique particle characteristics useful in identifying particle emissions from iron and steel manufacturing. Characterization of airborne particulate material collected in receptor areas was consistent with multiple atmospheric release events of kish particles from the local iron and steel facilities into neighboring residential areas. Kish particles deposited in nearby residential areas included an abundance of graphite flakes, tens of micrometers to millimeters in size, and spherical iron oxide particles, submicrometer to tens of micrometers in size. Bulk kish from local iron and steel facilities contained an abundance of similar particles. Approximately 60% of blast furnace kish by volume consisted of spherical iron oxide particles in the respirable size range. Basic oxygen furnace kish contained percent levels of strongly alkaline components such as calcium hydroxide. In addition, concentrations of respirable Mn in airborne particulate in residential areas and at local iron and steel facilities were approximately 1.6 and 53 times the inhalation reference concentration of 0.05 microg/m3 for chronic inhalation exposure of Mn, respectively. Thus, airborne release of kish may pose potential respirable particulate, corrosive, or toxic hazards for human health and/or a corrosive hazard for property and the environment.

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

    SciTech Connect

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

    2003-02-27

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

  2. Room air monitor for radioactive aerosols

    DOEpatents

    Balmer, David K.; Tyree, William H.

    1989-04-11

    A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-pre The U.S. Government has rights in this invention pursuant to Contract No. DE-AC04-76DP03533 between the Department of Energy and Rockwell International Corporation.

  3. Room air monitor for radioactive aerosols

    DOEpatents

    Balmer, D.K.; Tyree, W.H.

    1987-03-23

    A housing assembly for use with a room air monitor for simultaneous collection and counting of suspended particles includes a casing containing a combination detector-preamplifier system at one end, a filter system at the other end, and an air flow system consisting of an air inlet formed in the casing between the detector-preamplifier system and the filter system and an air passageway extending from the air inlet through the casing and out the end opposite the detector-preamplifier combination. The filter system collects suspended particles transported directly through the housing by means of the air flow system, and these particles are detected and examined for radioactivity by the detector-preamplifier combination. 2 figs.

  4. Airborne rescue system

    NASA Technical Reports Server (NTRS)

    Haslim, Leonard A. (Inventor)

    1991-01-01

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

  5. E-Alerts: Nuclear science and technology (radioactive wastes and radioactivity). E-mail newsletter

    SciTech Connect

    1999-05-01

    The newsletter discusses the following: Separation, processing, handling, storage, disposal, and reuse of radioactive wastes; Radioactive fallout; Fission products; Man-made or natural radioactivity; and Decommissioning.

  6. Bonded carbon or ceramic fiber composite filter vent for radioactive waste

    SciTech Connect

    Brassell, Gilbert W.; Brugger, Ronald P.

    1985-02-19

    Carbon bonded carbon fiber composites as well as ceramic or carbon bonded ceramic fiber composites are very useful as filters which can separate particulate matter from gas streams entraining the same. These filters have particular application to the filtering of radioactive particles, e.g., they can act as vents for containers of radioactive waste material.

  7. Size distributions of airborne radionuclides from the fukushima nuclear accident at several places in europe.

    PubMed

    Masson, Olivier; Ringer, Wolfgang; Malá, Helena; Rulik, Petr; Dlugosz-Lisiecka, Magdalena; Eleftheriadis, Konstantinos; Meisenberg, Olivier; De Vismes-Ott, Anne; Gensdarmes, François

    2013-10-01

    Segregation and radioactive analysis of aerosols according to their aerodynamic size were performed in France, Austria, the Czech Republic, Poland, Germany, and Greece after the arrival of contaminated air masses following the nuclear accident at the Fukushima Dai-ichi nuclear power plant in March 2011. On the whole and regardless of the location, the highest activity levels correspond either to the finest particle fraction or to the upper size class. Regarding anthropogenic radionuclides, the activity median aerodynamic diameter (AMAD) ranged between 0.25 and 0.71 μm for (137)Cs, from 0.17 to 0.69 μm for (134)Cs, and from 0.30 to 0.53 μm for (131)I, thus in the "accumulation mode" of the ambient aerosol (0.1-1 μm). AMAD obtained for the naturally occurring radionuclides (7)Be and (210)Pb ranged from 0.20 to 0.53 μm and 0.29 to 0.52 μm, respectively. Regarding spatial variations, AMADs did not show large differences from place to place compared with what was observed concerning bulk airborne levels registered on the European scale. When air masses arrived in Europe, AMADs for (131)I were about half those for cesium isotopes. Higher AMAD for cesium probably results from higher AMAD observed at the early stage of the accident in Japan. Lower AMAD for (131)I can be explained by the adsorption of gaseous iodine on particles of all sizes met during transport, especially for small particles. Additionally, weathering conditions (rain) encountered during transport and in Europe in March and April contributed to the equilibrium of the gaseous to total (131)I ratio. AMAD slightly increased with time for (131)I whereas a clear decreasing trend was observed with the AMADs for (137)Cs and (134)Cs. On average, the associated geometric standard deviation (GSD) appeared to be higher for iodine than for cesium isotopes. These statements also bear out a gaseous (131)I transfer on ambient particles of a broad size range during transport. Highest weighted activity levels were

  8. Study of proton radioactivities

    SciTech Connect

    Davids, C.N.; Back, B.B.; Henderson, D.J.

    1995-08-01

    About a dozen nuclei are currently known to accomplish their radioactive decay by emitting a proton. These nuclei are situated far from the valley of stability, and mark the very limits of existence for proton-rich nuclei: the proton drip line. A new 39-ms proton radioactivity was observed following the bombardment of a {sup 96}Ru target by a beam of 420-MeV {sup 78}Kr. Using the double-sided Si strip detector implantation system at the FMA, a proton group having an energy of 1.05 MeV was observed, correlated with the implantation of ions having mass 167. The subsequent daughter decay was identified as {sup 166}Os by its characteristic alpha decay, and therefore the proton emitter is assigned to the {sup 167}Ir nucleus. Further analysis showed that a second weak proton group from the same nucleus is present, indicating an isomeric state. Two other proton emitters were discovered recently at the FMA: {sup 171}Au and {sup 185}Bi, which is the heaviest known proton radioactivity. The measured decay energies and half-lives will enable the angular momentum of the emitted protons to be determined, thus providing spectroscopic information on nuclei that are beyond the proton drip line. In addition, the decay energy yields the mass of the nucleus, providing a sensitive test of mass models in this extremely proton-rich region of the chart of the nuclides. Additional searches for proton emitters will be conducted in the future, in order to extend our knowledge of the location of the proton drip line.

  9. Laser Doppler spectrometer method of particle sizing. [for air pollution

    NASA Technical Reports Server (NTRS)

    Weber, F. N.

    1976-01-01

    A spectrometer for the detection of airborne particulate pollution in the submicron size range is described. In this device, airborne particles are accelerated through a supersonic nozzle, with different sizes achieving different velocities in the gas flow. Information about the velocities of the accelerated particles is obtained with a laser-heterodyne optical system through the Doppler shift of light scattered from the particles. Detection is accomplished by means of a photomultiplier. Nozzle design and signal processing techniques are also discussed.

  10. Radioactive and magnetic investigations

    NASA Technical Reports Server (NTRS)

    Heye, D.; Beiersdorf, H.

    1979-01-01

    Age and growth pattern determination of manganese nodules were explored. Two methods are discussed: (1) measurement of the presence of radioactive iodine isotopes; which is effective only up to 3.105 years, and (2) measurements of magnetism. The growth rates of three nodules were determined. The surface of the nodule was recent, and the overall age of the nodule could be determined with accuracy of better than 30%. Measurement of paleomagnetic effect was attempted to determine wider age ranges, however, the measured sign changes could not be interpreted as paleomagnetic reversals.

  11. Material for radioactive protection

    DOEpatents

    Taylor, R.S.; Boyer, N.W.

    A boron containing burn resistant, low-level radiation protection material useful, for example, as a liner for radioactive waste disposal and storage, a component for neutron absorber, and a shield for a neutron source is described. The material is basically composed of borax in the range of 25 to 50%, coal tar in the range of 25 to 37.5%, with the remainder being an epoxy resin mix. A preferred composition is 50% borax, 25% coal tar and 25% epoxy resin. The material is not susceptible to burning and is about 1/5 the cost of existing radiation protection material utilized in similar applications.

  12. Radioactive waste material disposal

    DOEpatents

    Forsberg, Charles W.; Beahm, Edward C.; Parker, George W.

    1995-01-01

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide.

  13. Radioactive waste material disposal

    DOEpatents

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1995-10-24

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide. 3 figs.

  14. Integrated micro-optofluidic platform for real-time detection of airborne microorganisms

    NASA Astrophysics Data System (ADS)

    Choi, Jeongan; Kang, Miran; Jung, Jae Hee

    2015-11-01

    We demonstrate an integrated micro-optofluidic platform for real-time, continuous detection and quantification of airborne microorganisms. Measurements of the fluorescence and light scattering from single particles in a microfluidic channel are used to determine the total particle number concentration and the microorganism number concentration in real-time. The system performance is examined by evaluating standard particle measurements with various sample flow rates and the ratios of fluorescent to non-fluorescent particles. To apply this method to real-time detection of airborne microorganisms, airborne Escherichia coli, Bacillus subtilis, and Staphylococcus epidermidis cells were introduced into the micro-optofluidic platform via bioaerosol generation, and a liquid-type particle collection setup was used. We demonstrate successful discrimination of SYTO82-dyed fluorescent bacterial cells from other residue particles in a continuous and real-time manner. In comparison with traditional microscopy cell counting and colony culture methods, this micro-optofluidic platform is not only more accurate in terms of the detection efficiency for airborne microorganisms but it also provides additional information on the total particle number concentration.

  15. Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors.

    PubMed

    McLean, Thomas D; Moore, Murray E; Justus, Alan L; Hudston, Jonathan A; Barbé, Benoît

    2016-11-01

    Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. The Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached to the watch's minute hand, and as it rotates, more of the underlying source is revealed. The measured alpha activity increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. Data obtained using the Dynamic Radioactive Source has been used to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.

  16. Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors

    SciTech Connect

    McLean, Thomas D.; Moore, Murray E.; Justus, Alan L.; Hudston, Jonathan A.; Barbé, Benoît

    2016-01-01

    Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. Furthermore, the Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached to the watch’s minute hand, and as it rotates, more of the underlying source is revealed. The alpha activity we measured increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. We also used data obtained using the Dynamic Radioactive Source to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.

  17. Dynamic Radioactive Source for Evaluating and Demonstrating Time-dependent Performance of Continuous Air Monitors

    DOE PAGES

    McLean, Thomas D.; Moore, Murray E.; Justus, Alan L.; ...

    2016-01-01

    Evaluation of continuous air monitors in the presence of a plutonium aerosol is time intensive, expensive, and requires a specialized facility. The Radiation Protection Services Group at Los Alamos National Laboratory has designed a Dynamic Radioactive Source, intended to replace plutonium aerosol challenge testing. Furthermore, the Dynamic Radioactive Source is small enough to be inserted into the sampler filter chamber of a typical continuous air monitor. Time-dependent radioactivity is introduced from electroplated sources for real-time testing of a continuous air monitor where a mechanical wristwatch motor rotates a mask above an alpha-emitting electroplated disk source. The mask is attached tomore » the watch’s minute hand, and as it rotates, more of the underlying source is revealed. The alpha activity we measured increases with time, simulating the arrival of airborne radioactive particulates at the air sampler inlet. The Dynamic Radioactive Source allows the temporal behavior of puff and chronic release conditions to be mimicked without the need for radioactive aerosols. The new system is configurable to different continuous air monitor designs and provides an in-house testing capability (benchtop compatible). It is a repeatable and reusable system and does not contaminate the tested air monitor. Test benefits include direct user control, realistic (plutonium) aerosol spectra, and iterative development of continuous air monitor alarm algorithms. We also used data obtained using the Dynamic Radioactive Source to elucidate alarm algorithms and to compare the response time of two commercial continuous air monitors.« less

  18. Characterization of iron in airborne particulate matter

    NASA Astrophysics Data System (ADS)

    Tavares, F. V. F.; Ardisson, J. D.; Rodrigues, P. C. H.; Brito, W.; Macedo, W. A. A.; Jacomino, V. M. F.

    2014-01-01

    In this work soil samples, iron ore and airborne atmospheric particulate matter (PM) in the Metropolitan Region of Belo Horizonte (MRBH), State of Minas Gerais, Brazil, are investigated with the aim of identifying if the sources of the particulate matter are of natural origin, such as, resuspension of particles from soil, or due to anthropogenic origins from mining and processing of iron ore. Samples were characterized by powder X-ray diffraction, X-ray fluorescence and 57Fe-Mössbauer spectroscopy. The results showed that soil samples studied are rich in quartz and have low contents of iron mainly iron oxide with low crystallinity. The samples of iron ore and PM have high concentration of iron, predominantly well crystallized hematite. 57Fe-Mössbauer spectroscopy confirmed the presence of similar iron oxides in samples of PM and in the samples of iron ore, indicating the anthropogenic origin in the material present in atmosphere of the study area.

  19. Radioactive materials released from nuclear power plants. Annual report 1991, Volume 12

    SciTech Connect

    Tichler, J.; Doty, K.; Congemi, J.

    1994-05-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1991 have been compiled and reported. Data on solid waste shipments as well as selected operating inf