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https://www.readbyqxmd.com/read/28646774/observations-of-black-carbon-aerosols-characteristics-over-an-urban-environment-radiative-forcing-and-related-implications
#1
Samina Bibi, Khan Alam, Farrukh Chishtie, Humera Bibi, Said Rahman
With observations of black carbon (BC) aerosol concentrations, optical and radiative properties were obtained over the urban city of Karachi during the period of March 2006-December 2008. BC concentrations were continuously measured using an Aethalometer, while optical and radiative properties were estimated through the Optical Properties of Aerosols and Clouds (OPAC) and Santa Barbra DISORT Atmospheric Radiative Transfer (SBDART) models, respectively. For the study period, the measured BC concentrations were higher during January, February and November, while lower during May, June, July and August...
June 21, 2017: Science of the Total Environment
https://www.readbyqxmd.com/read/28646737/pollution-characteristics-and-source-identification-of-trace-metals-in-riparian-soils-of-miyun-reservoir-china
#2
Lanfang Han, Bo Gao, Jin Lu, Yang Zhou, Dongyu Xu, Li Gao, Ke Sun
The South-to-North Water Diversion Project, one of China's largest water diversion projects, has aroused widespread concerns about its potential ecological impacts, especially the potential release of trace metals from shoreline soils into Miyun Reservoir (MYR). Here, riparian soil samples from three elevations and four types of land use were collected. Soil particle size distributions, contents and chemical fractionations of trace metals and lead (Pb) isotopic compositions were analyzed. Results showed that soil texture was basically similar in four types of land use, being mainly composed of sand, with minor portions of clay and silt, while recreational land contained more abundant chromium (Cr), copper (Cu), zinc (Zn) and cadmium (Cd), suggesting a possible anthropogenic source for this soil pollution...
June 21, 2017: Ecotoxicology and Environmental Safety
https://www.readbyqxmd.com/read/28646605/observations-and-impacts-of-bleach-washing-on-indoor-chlorine-chemistry
#3
J P S Wong, N Carslaw, R Zhao, S Zhou, J P D Abbatt
Ambient levels of chlorinated gases and aerosol components were measured by on-line chemical ionization and aerosol mass spectrometers after an indoor floor was repeatedly washed with a commercial bleach solution. Gaseous chlorine (Cl2 , 10's of ppbv) and hypochlorous acid (HOCl, 100's of ppbv) arise after floor washing, along with nitryl chloride (ClNO2 ), dichlorine monoxide (Cl2 O) and chloramines (NHCl2 , NCl3 ). Much higher mixing ratios would prevail in a room with lower and more commonly encountered air exchange rates than that observed in the study (12...
June 24, 2017: Indoor Air
https://www.readbyqxmd.com/read/28646325/anti-tuberculosis-bacteriophage-d29-delivery-with-a-vibrating-mesh-nebulizer-jet-nebulizer-and-soft-mist-inhaler
#4
Nicholas B Carrigy, Rachel Y Chang, Sharon S Y Leung, Melissa Harrison, Zaritza Petrova, Welkin H Pope, Graham F Hatfull, Warwick J Britton, Hak-Kim Chan, Dominic Sauvageau, Warren H Finlay, Reinhard Vehring
PURPOSE: To compare titer reduction and delivery rate of active anti-tuberculosis bacteriophage (phage) D29 with three inhalation devices. METHODS: Phage D29 lysate was amplified to a titer of 11.8 ± 0.3 log10(pfu/mL) and diluted 1:100 in isotonic saline. Filters captured the aerosolized saline D29 preparation emitted from three types of inhalation devices: 1) vibrating mesh nebulizer; 2) jet nebulizer; 3) soft mist inhaler. Full-plate plaque assays, performed in triplicate at multiple dilution levels with the surrogate host Mycobacterium smegmatis, were used to quantify phage titer...
June 23, 2017: Pharmaceutical Research
https://www.readbyqxmd.com/read/28646113/aerosolization-of-mycotoxins-after-growth-of-toxinogenic-fungi-on-wallpaper
#5
Brankica Aleksic, Marjorie Draghi, Sebastien Ritoux, Sylviane Bailly, Marlène Lacroix, Isabelle P Oswald, Jean-Denis Bailly, Enric Robine
Many fungi can develop on building material in indoor environments if moisture is high enough. Among species that are frequently observed, some are known to be potent mycotoxin producers. This presence of toxinogenic fungi in indoor environments raises the question of the possible exposure of occupants to these toxic compounds by inhalation after aerosolization.This study investigated the mycotoxin production by Penicillium brevicompactum, Aspergillus versicolor and Stachybotrys chartarum during their growth on wallpaper and the possible subsequent aerosolization of produced mycotoxins from contaminated substrates...
June 23, 2017: Applied and Environmental Microbiology
https://www.readbyqxmd.com/read/28644613/impact-of-thermal-decomposition-on-thermal-desorption-instruments-advantage-of-thermogram-analysis-for-quantifying-volatility-distributions-of-organic-species
#6
Harald Stark, Reddy L N Yatavelli, Samantha L Thompson, Hyungu Kang, Jordan Edward Krechmer, Joel R Kimmel, Brett B Palm, Weiwei Hu, Patrick L Hayes, Douglas A Day, Pedro Campuzano-Jost, Manjula R Canagaratna, John T Jayne, Douglas R Worsnop, Jose L Jimenez
We present results from a high-resolution chemical ionization time-of-flight mass spectrometer (HRToF-CIMS), operated with two different thermal desorption inlets, designed to characterize the gas and aerosol composition. Data from two field campaigns at forested sites are shown. Particle volatility distributions are estimated using three different methods: thermograms, elemental formulas, and measured partitioning. Thermogram-based results are consistent with those from an aerosol mass spectrometer (AMS) with a thermal denuder, implying that thermal desorption is reproducible across very different experimental setups...
June 23, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28644205/the-unrecognized-epidemic-of-electronic-cigarette-burns
#7
Jesus I Ramirez, Catherine A Ridgway, Jeanne G Lee, Bruce M Potenza, Soman Sen, Tina L Palmieri, David G Greenhalgh, Pirko Maguina
Electronic cigarettes (e-cigarettes) are novel battery-operated devices that deliver nicotine as an inhaled aerosol. They originated from China in 2007 and their use has rapidly increased worldwide in the past decade, yet they remain largely unregulated. Reports of injuries associated with their use have appeared as unusual events in the news media and as case reports in the medical literature. This study was undertaken to explore e-cigarettes as a mechanism of burn injury. Referral records to three burn centers from January 2007 to July 2016 were searched to identify patients with injuries caused by e-cigarettes...
July 2017: Journal of Burn Care & Research: Official Publication of the American Burn Association
https://www.readbyqxmd.com/read/28643829/efficient-scavenging-of-criegee-intermediates-on-water-by-surface-active-cis-pinonic-acid
#8
Shinichi Enami, A J Colussi
cis-Pinonic acid (CPA), the main product of the atmospheric oxidation of biogenic α-pinene emissions and a major component of secondary organic aerosol (SOA), is a potentially key species en route to extremely low volatility compounds. Here, we report that CPA is an exceptionally efficient scavenger of Criegee intermediates (CIs) on aqueous surfaces. Against expectations, millimolar CPA (a surface-active C10 keto-carboxylic acid possessing a rigid skeleton) is able to compete with 23 M bulk water for the CIs produced in the ozonolysis of sesquiterpene solutes by O3(g) on the surface of a water:acetonitrile solvent...
June 23, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28643076/scintigraphic-peritoneography-reveals-a-non-uniform-99m-tc-pertechnetat-aerosol-distribution-pattern-for-pressurized-intra-peritoneal-aerosol-chemotherapy-pipac-in-a-swine-model
#9
Alexander Bellendorf, Veria Khosrawipour, Tanja Khosrawipour, Simon Siebigteroth, Joseph Cohnen, David Diaz-Carballo, Andreas Bockisch, Jürgen Zieren, Urs Giger-Pabst
BACKGROUND: Although recent data are contradictory, it is still claimed that Pressurized Intra-Peritoneal Aerosol Chemotherapy (PIPAC) would deliver an aerosol which distributes homogeneously throughout the entire abdominal cavity. METHODS: (99m)Tc-Pertechnetat was administered in four postmortem swine using either PIPAC or liquid intra-peritoneal chemotherapy (IPC). The animals were examined by planar scintigraphy and SPECT/CT. Planar distribution images were divided into four regions of interest (ROIs: right/left upper and lower abdominal quadrant)...
June 22, 2017: Surgical Endoscopy
https://www.readbyqxmd.com/read/28641420/nh3-as-unique-non-classical-content-former-within-clathrate-hydrates
#10
Zafer Maşlakcı, J Paul Devlin, Nevin Uras-Aytemiz
High quality FTIR spectra of aerosols of NH3-THF and NH3-TMO binary clathrate hydrates (CHs) have been measured. Our recently developed all-vapor sub-second approach to clathrate-hydrate formation combined with computational studies has been used to identify vibrational spectroscopic signatures of NH3 within the gas hydrates. The present study shows that there are three distinct NH3 types, namely, classical small-cage NH3, nonclassical small-cage NH3, and NH3 within the hydrate network. The network ammonia does not directly trigger the non-classical CH structure...
June 21, 2017: Journal of Chemical Physics
https://www.readbyqxmd.com/read/28641196/c1-c2-alkyl-aminiums-in-urban-aerosols-insights-from-ambient-and-fuel-combustion-emission-measurements-in-the-yangtze-river-delta-region-of-china
#11
Wenchao Shen, Lili Ren, Yi Zhao, Luyu Zhou, Liang Dai, Xinlei Ge, Shaofei Kong, Qin Yan, Honghui Xu, Yujun Jiang, Jun He, Mindong Chen, Huan Yu
We measured low molar-mass alkyl aminiums (methylaminium, dimethylaminium, ethylaminium and diethylaminium) in urban aerosols in the Yangtze River Delta region of eastern China in August 2014 and from November 2015 to May 2016. After examining artifact formation on sample filters, methylaminium, dimethylaminium and ethylaminium concentrations were quantified. The three C1-C2 aminiums exhibited a unimodal size distribution that maximized between 0.56 and 1.0 μm. Their concentrations in PM2.5 were 5.7 ± 3...
June 19, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/28640607/primary-and-photochemically-aged-aerosol-emissions-from-biomass-cookstoves-chemical-and-physical-characterization
#12
Stephen M Reece, Aditya Sinha, Andrew P Grieshop
Secondary organic aerosol (SOA) formation during photo-oxidation of primary emissions from cookstoves used in developing countries may make important contributions to their climate and air quality impacts. We present results from laboratory experiments with a field portable oxidation flow reactor (F-OFR) to study the evolution of emissions over hours to weeks of equivalent atmospheric aging. Lab tests, using dry red oak, measured fresh and aged emissions from a 3 stone fire (TSF), a "rocket" natural draft stove (NDS) and a forced draft gasifier stove (FDGS), in order of increasing modified combustion efficiency (MCE) and decreasing particulate matter emission factors (EF)...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640603/changes-in-light-absorptivity-of-molecular-weight-separated-brown-carbon-due-to-photolytic-aging
#13
Jenny Pui Shan Wong, Athanasios Nenes, Rodney J Weber
Brown carbon (BrC) are those organic compounds in atmospheric aerosols that absorb solar radiation and may play an important role on planetary radiative forcing and climate. However, little is known about the production and loss mechanisms of BrC in the atmosphere. Here, we study how the light absorptivity of BrC from wood smoke and secondary BrC generated from reaction of ammonium sulfate with methylglyoxal changes under photolytic aging by UVA radiation in the aqueous phase. Owing to its chemical complexity, BrC is separated by molecular weight using size exclusion chromatography and the response of each molecular weight fraction to aging is studied...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640598/structural-and-light-absorption-characteristics-of-complex-water-insoluble-organic-mixtures-in-urban-submicron-aerosols
#14
Qingcai Chen, Fumikazu Ikemori, Yuua Nakamura, Petr Vodicka, Kimitaka Kawamura, Michihiro Mochida
Submicrometer aerosols in the urban atmosphere of Nagoya, Japan, were collected in late winter and early spring, and the water-insoluble organic matter (WISOM) in the samples were fractionated into six subfractions based on their polarities by using solvent and normal-phase solid-phase extractions: non-polar (F1), low-polar (F2 and F3), and medium-polar (F4, F5, and F6) fractions. The overall structural characteristics of these subfractions were then analyzed using Fourier transform infrared spectroscopy, nuclear magnetic resonance spectroscopy, and high-resolution aerosol mass spectrometry...
June 22, 2017: Environmental Science & Technology
https://www.readbyqxmd.com/read/28640319/observational-constraints-on-particle-acidity-using-measurements-and-modelling-of-particles-and-gases
#15
J G Murphy, P K Gregoire, A G Tevlin, G R Wentworth, R A Ellis, M Z Markovic, T C VandenBoer
In many parts of the world, the implementation of air quality regulations has led to significant decreases in SO2 emissions with minimal impact on NH3 emissions. In Canada and the United States, the molar ratio of NH3 : SO2 emissions has increased dramatically between 1990 and 2014. In many regions of North America, this will lead the molar ratio of NHx : SO4, where NHx is the sum of particle phase NH4(+) and gas phase NH3, and SO4 is the sum of particle phase HSO4(-) and SO4(2-), to exceed 2. A thermodynamic model (E-AIM model II) is used to investigate the sensitivity of particle pH, and the gas-particle partitioning of NHx and inorganic nitrate, to the atmospheric NHx : SO4 ratio...
June 22, 2017: Faraday Discussions
https://www.readbyqxmd.com/read/28640263/strong-constraints-on-aerosol-cloud-interactions-from-volcanic-eruptions
#16
Florent F Malavelle, Jim M Haywood, Andy Jones, Andrew Gettelman, Lieven Clarisse, Sophie Bauduin, Richard P Allan, Inger Helene H Karset, Jón Egill Kristjánsson, Lazaros Oreopoulos, Nayeong Cho, Dongmin Lee, Nicolas Bellouin, Olivier Boucher, Daniel P Grosvenor, Ken S Carslaw, Sandip Dhomse, Graham W Mann, Anja Schmidt, Hugh Coe, Margaret E Hartley, Mohit Dalvi, Adrian A Hill, Ben T Johnson, Colin E Johnson, Jeff R Knight, Fiona M O'Connor, Daniel G Partridge, Philip Stier, Gunnar Myhre, Steven Platnick, Graeme L Stephens, Hanii Takahashi, Thorvaldur Thordarson
Aerosols have a potentially large effect on climate, particularly through their interactions with clouds, but the magnitude of this effect is highly uncertain. Large volcanic eruptions produce sulfur dioxide, which in turn produces aerosols; these eruptions thus represent a natural experiment through which to quantify aerosol-cloud interactions. Here we show that the massive 2014-2015 fissure eruption in Holuhraun, Iceland, reduced the size of liquid cloud droplets-consistent with expectations-but had no discernible effect on other cloud properties...
June 22, 2017: Nature
https://www.readbyqxmd.com/read/28640202/evaluation-of-legionella-air-contamination-in-healthcare-facilities-by-different-sampling-methods-an-italian-multicenter-study
#17
Maria Teresa Montagna, Osvalda De Giglio, Maria Luisa Cristina, Christian Napoli, Claudia Pacifico, Antonella Agodi, Tatjana Baldovin, Beatrice Casini, Maria Anna Coniglio, Marcello Mario D'Errico, Santi Antonino Delia, Maria Grazia Deriu, Marco Guida, Pasqualina Laganà, Giorgio Liguori, Matteo Moro, Ida Mura, Francesca Pennino, Gaetano Privitera, Vincenzo Romano Spica, Silvia Sembeni, Anna Maria Spagnolo, Stefano Tardivo, Ida Torre, Federica Valeriani, Roberto Albertini, Cesira Pasquarella
Healthcare facilities (HF) represent an at-risk environment for legionellosis transmission occurring after inhalation of contaminated aerosols. In general, the control of water is preferred to that of air because, to date, there are no standardized sampling protocols. Legionella air contamination was investigated in the bathrooms of 11 HF by active sampling (Surface Air System and Coriolis(®)μ) and passive sampling using settling plates. During the 8-hour sampling, hot tap water was sampled three times. All air samples were evaluated using culture-based methods, whereas liquid samples collected using the Coriolis(®)μ were also analyzed by real-time PCR...
June 22, 2017: International Journal of Environmental Research and Public Health
https://www.readbyqxmd.com/read/28638425/the-effect-of-wood-aerosols-and-bioaerosols-on-the-respiratory-systems-of-wood-manufacturing-industry-workers-in-golestan-province
#18
Phateme Badirdast, Mansour Rezazadeh Azari, Soussan Salehpour, Ali Ghadjari, Soheila Khodakarim, Davod Panahi, Moslem Fadaei, Abolfazl Rahimi
BACKGROUND: Occupational exposure to dust leads to acute and chronic respiratory diseases, occupational asthma, and depressed lung function. In the light of a lack of comprehensive studies on the exposure of Iranian workers to wood dusts, the objective of this study was to monitor the occupational exposure to wood dust and bioaerosol, and their correlation with the lung function parameters in chipboard manufacturing industry workers. MATERIALS AND METHODS: A cross-sectional study was conducted on chipboard workers in Golestan Province; a total of 150 men (100 exposed cases and 50 controls) were assessed...
2017: Tanaffos
https://www.readbyqxmd.com/read/28638174/near-real-time-measurement-of-carbonaceous-aerosol-using-microplasma-spectroscopy-application-to-measurement-of-carbon-nanomaterials
#19
Lina Zheng, Pramod Kulkarni, M Eileen Birch, Gregory Deye, Dionysios D Dionysiou
A sensitive, field-portable microplasma spectroscopy method has been developed for real-time measurement of carbon nanomaterials. The method involves microconcentration of aerosol on a microelectrode tip for subsequent analysis for atomic carbon using laser-induced breakdown spectroscopy (LIBS) or spark emission spectroscopy (SES). The spark-induced microplasma was characterized by measuring the excitation temperature (15,000 - 35,000 K), electron density (1.0 × 10(17) - 2.2 × 10(17) cm(-3)), and spectral responses as functions of time and interelectrode distance...
August 18, 2016: Aerosol Science and Technology: the Journal of the American Association for Aerosol Research
https://www.readbyqxmd.com/read/28638167/computational-fluid-dynamics-analysis-of-the-venturi-dustiness-tester
#20
Prahit Dubey, Urmila Ghia, Leonid A Turkevich
Dustiness quantifies the propensity of a finely divided solid to be aerosolized by a prescribed mechanical stimulus. Dustiness is relevant wherever powders are mixed, transferred or handled, and is important in the control of hazardous exposures and the prevention of dust explosions and product loss. Limited quantities of active pharmaceutical powders available for testing led to the development (at University of North Carolina) of a Venturi-driven dustiness tester. The powder is turbulently injected at high speed (Re ~ 2 × 10(4)) into a glass chamber; the aerosol is then gently sampled (Re ~ 2 × 10(3)) through two filters located at the top of the chamber; the dustiness index is the ratio of sampled to injected mass of powder...
May 2017: Powder Technology
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