Showing papers in "Aerosol Science and Technology in 2021"
TL;DR: Particle-size dependent filtration efficiencies (FE; dp) as mentioned in this paper were used in the COVID-19 pandemic caused by the SARS-CoV-2 virus.
Abstract: As a consequence of the COVID-19 pandemic caused by the SARS-CoV-2 virus, the widespread daily use of face masks is promoted worldwide. Particle-size dependent filtration efficiencies (FE; dp = 30 ...
132 citations
TL;DR: The results suggest that the persistence of infectious SARS-CoV-2 in naturally occurring aerosols may be affected by environmental conditions, and that aerosolized virus could remain infectious for extended periods of time under some environmental conditions.
Abstract: Recent evidence suggests that respiratory aerosols may play a role in the spread of SARS-CoV-2 during the ongoing COVID-19 pandemic. Our laboratory has previously demonstrated that simulated sunlig...
120 citations
TL;DR: The results suggest that face masks and neck gaiters are preferable to face shields as source control devices for cough aerosols.
Abstract: Face masks are recommended to reduce community transmission of SARS-CoV-2. One of the primary benefits of face masks and other coverings is as source control devices to reduce the expulsion of resp...
119 citations
TL;DR: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted in an unprecedented shutdown in social and economic activity, with the cultural sector particularly severely affected.
Abstract: The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic has resulted in an unprecedented shutdown in social and economic activity, with the cultural sector particularly severely a
117 citations
TL;DR: A three-layer mask consisting of outer layers of a flexible, tightly woven fabric and an inner layer consisting of a material designed to filter out particles is recommended, which should produce an overall efficiency of >70% at the most penetrating particle size and >90% for particles 1 m and larger if the mask fits well.
Abstract: We evaluated the effectiveness of 11 face coverings for material filtration efficiency, inward protection efficiency on a manikin, and outward protection efficiency on a manikin. At the most penetr...
108 citations
TL;DR: In this paper, the authors established that airborne transmission of SARS-CoV-2 through virus-containing aerosol particles has been established as an important pathway for Covid-19 infection.
Abstract: Airborne transmission of SARS-CoV-2 through virus-containing aerosol particles has been established as an important pathway for Covid-19 infection. Suitable measures to prevent such infections are ...
102 citations
TL;DR: Masks always reduce droplets and aerosols emitted by COVID-19 symptomatic and asymptomatic persons, reducing SARS-CoV-2 contamination.
Abstract: The use of face masks is mandatory in public places in many countries to slow the spread of the COVID-19 pandemic. In developing countries, homemade masks with varying techniques and fabrics are us...
39 citations
TL;DR: In this article, the demand for face masks that meet medical or workplace standards can prevent most of the aerosol and droplet transmission during a COVID-19 pandemic in 2020.
Abstract: During a pandemic in which aerosol and droplet transmission is possible, such as the COVID-19 pandemic of 2020, the demand for face masks that meet medical or workplace standards can prevent most i...
33 citations
TL;DR: In this article, the effectiveness of various face coverings to reduce the spread of SARS-CoV-2 virus during the COVID-19 pandemic was investigated and compared.
Abstract: Exposure to respiratory droplets contributes greatly to the spread of SARS-CoV-2 virus during the COVID-19 pandemic. This study investigates the effectiveness of various face coverings to reduce co...
32 citations
TL;DR: In this article, a universal mask wearing is recommended to help control the spread of COVID-19, which reduces the expulsion of aerosols of respiratory fluids into the environment (called source control).
Abstract: Universal mask wearing is recommended to help control the spread of COVID-19. Masks reduce the expulsion of aerosols of respiratory fluids into the environment (called source control) and offer som...
29 citations
TL;DR: It is found that two-layers of cotton fabric can provide a comfortable, breathable and reusable option and can significantly improve filtration and block expiratory aerosols at the expense of an added pressure drop.
Abstract: The goal of this study is to evaluate the filtration efficiency and breathability of improvised filtration and commonly available mask materials, as well as to assess their reusability. Materials r...
TL;DR: In this paper, the imaginary part of the refractive indices (k) of brown carbon (BrC) retrieved from online and solvent-extraction offline light-absorption measurements was compared.
Abstract: We compared the imaginary part of the refractive indices (k) of brown carbon (BrC) retrieved from online and solvent-extraction offline light-absorption measurements. BrC with variable light-absorp...
TL;DR: In this paper, the first COVID-19 related bus studies to fully characterize cough aerosol dispersion and control in the highly turbulent real-world environment of driving regular bus routes are presented.
Abstract: This study is one of the first COVID-19 related bus studies to fully characterize cough aerosol dispersion and control in the highly turbulent real-world environment of driving regular bus routes o...
TL;DR: In this article, the authors assess the risk of aerosol transmission of SARS-CoV-2, using measurements of the airborne viral concentrations in proximity to infected individuals, the persistence of the virus in aerosols, and the d
Abstract: To assess the risk of aerosol transmission of SARS-CoV-2, measurements of the airborne viral concentrations in proximity to infected individuals, the persistence of the virus in aerosols, and the d
TL;DR: The Aerodyne aerosol mass spectrometer (AMS) is used extensively to study the composition of non-refractory submicron aerosol composition during atmospheric field studies.
Abstract: The Aerodyne aerosol mass spectrometer (AMS) is used extensively to study the composition of non-refractory submicron aerosol composition during atmospheric field studies. During two recent studies...
TL;DR: The number of respiratory particles produced by breathing, coughing, and speaking or generated during medical procedures serve as important routes for disease transmission as mentioned in this paper, and the number of particles generated by these activities is a good indicator of disease transmission.
Abstract: Respiratory particles produced by breathing, coughing, and speaking or generated during medical procedures serve as important routes for disease transmission. Characterizing the number of particles...
TL;DR: In this article, the composition of wildfire smoke particulate matter (PM) was investigated during a 2018 smoke episode in the San Francisco Bay Area and compared to non-wildfire periods.
Abstract: The composition of wildfire smoke particulate matter (PM) was investigated during a 2018 smoke episode in the San Francisco Bay Area and compared to non-wildfire periods. Scanning electron microsco...
TL;DR: In this paper, an indicator for the occurrence of new particle formation (NPF) in various atmospheric environments is proposed, which is a major source of ultrafine particles in the atmosphere.
Abstract: New particle formation (NPF) occurs frequently in various atmospheric environments and it is a major source of ultrafine particles. This study proposes an indicator, I, for the occurrence of NPF in...
TL;DR: The miniCAST 5201 black carbon (BC) generator as mentioned in this paper is a soot generator able to produce soot particles with a wide range of properties in a stable and reproducible manner.
Abstract: The miniCAST 5201 black carbon (BC) generator is a novel soot generator able to produce soot particles with a wide range of properties in a stable and reproducible manner. In this study, particles ...
TL;DR: The COVID-19 pandemic has resulted in a severe shortage of personal protective equipment as mentioned in this paper and the World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) recommend to use personal protection equipment.
Abstract: The COVID-19 pandemic has resulted in a severe shortage of personal protective equipment. The World Health Organization (WHO) and the US Centers for Disease Control and Prevention (CDC) recommend t...
TL;DR: This work demonstrates a methodology to obtain distribution and viability of microorganism deposited on surface, and suggests guidelines to setting up a protective partition as a possible intervention method against disease transmission.
Abstract: Knowledge of respiratory bacterium/virus distribution on surfaces is critical for studying disease transmission via the contact route. Here, we investigated the bioaerosol deposition and distributi...
TL;DR: The Filter Inlet for Gases and AEROsols coupled with a chemical ionization mass spectrometer (FIGAERO-CIMS) measures particle-phase organics via temperature-programmed thermal desorption, though th...
Abstract: The Filter Inlet for Gases and AEROsols coupled with a chemical ionization mass spectrometer (FIGAERO-CIMS) measures particle-phase organics via temperature-programmed thermal desorption, though th...
TL;DR: In this paper, the nonvolatile particle number emissions of three bi-fuel passenger cars (Euro 6b, 6d-temp), which operate on compressed natural gas (CNG), as a primary fuel, and ga...
Abstract: The current study investigates the nonvolatile particle number emissions of three bi-fuel passenger cars (Euro 6b, 6d-temp), which operate on compressed natural gas (CNG), as a primary fuel, and ga...
TL;DR: Very few measurements exist of the composition and contribution to cloud condensation nuclei (CCN) of organic mass (OM) at different sizes for particles over the Southern Ocean as discussed by the authors.
Abstract: Very few measurements exist of the composition and contribution to cloud condensation nuclei (CCN) of organic mass (OM) at different sizes for particles over the Southern Ocean. Airborne and shipbo...
TL;DR: Measurements of aerosol and droplet concentrations generated when playing woodwind and brass instruments and comparisons with breathing, speaking, and singing suggest that playing instruments generates less aerosol than speaking or singing at high volumes.
Abstract: The performing arts have been significantly restricted due to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic. We report measurements of aerosol and droplet concentrations...
University of Helsinki1, University of Eastern Finland2, Goethe University Frankfurt3, California Institute of Technology4, University of Lisbon5, Paul Scherrer Institute6, University of Vienna7, Carnegie Mellon University8, University of Colorado Boulder9, University of Innsbruck10, Russian Academy of Sciences11, Nanjing University12, CERN13, University of Beira Interior14, Finnish Meteorological Institute15, Beijing University of Chemical Technology16
TL;DR: Ions enhance the formation rate of atmospheric aerosol particles, which play an important role in Earth's radiative balance as discussed by the authors, and ion-induced nucleation involves the stepwise accretion of neutral monome...
Abstract: Ions enhance the formation rate of atmospheric aerosol particles, which play an important role in Earth’s radiative balance. Ion-induced nucleation involves the stepwise accretion of neutral monome...
TL;DR: In this paper, a classroom with 25 students was considered as an indoor space, and an attempt was made to devise a method to reduce the concentration of the viruses generated indoors more effectively.
Abstract: Coronavirus disease (COVID-19) has infected many people worldwide. As the probability of being infected by the virus increases with an increase in the number of people gathered in an indoor space, methods for reducing its spread indoors are urgently required. In this study, a classroom with 25 students was considered as an indoor space, and an attempt was made to devise a method to reduce the concentration of the viruses generated indoors more effectively. Through numerical analysis, the age of air inside the classroom was compared and analyzed when both the air cleaner and natural ventilation were used. The age of air varied locally in the classroom depending on the position of the air cleaner, confirming its importance in effectively removing particles possibly containing viruses generated indoors. When the air cleaner flow rate was doubled, the age of air was almost halved, implying that the concentration of the particles including viruses generated indoors can be reduced efficiently by increasing the air cleaner flow rate. Natural ventilation performed by completely opening the windows and doors of the classroom reduced the age of air. It was observed that the operation of the air cleaner along with open windows and doors of the classroom reduced the concentration of the particles including viruses generated indoors more effectively. More specifically, when both natural ventilation and air cleaner were applied, the age of air decreased by almost 50% compared with the only air cleaner case and by about 22% compared with the only natural ventilation case. Copyright (c) 2021 American Association for Aerosol Research
TL;DR: In this article, the study of biomass burning particle density provides information on aging, new particle formation, transport properties, and is an important parameter in aerosol impacts modeling, where density is used.
Abstract: The study of biomass burning particle density provides information on aging, new particle formation, transport properties, and is an important parameter in aerosol impacts modeling. Density is used...
TL;DR: A short distance between infected persons and exposed persons can probably result in a high risk of respiratory infection as mentioned in this paper, and they experimentally investigated the short-range bioaerosol depositio...
Abstract: A short distance between infected persons and exposed persons can probably result in a high risk of respiratory infection. This work experimentally investigated the short-range bioaerosol depositio...
TL;DR: In this paper, the authors measured the aerosol particle size of electronic cigarettes and found that the volatile and dynamic nature of these aerosols makes it difficult to measure the particle size.
Abstract: Measuring the aerosol particle size of electronic cigarettes can be particularly challenging due to the volatile and dynamic nature of these aerosols. In particular, electronic cigarette aerosol pa...