A5005962572- Infection Control and Ventilation
- Air Quality and Health Impacts
- COVID-19 epidemiological studies
- Vehicle emissions and performance
- Atmospheric chemistry and aerosols
- Air Quality Monitoring and Forecasting
- COVID-19 and healthcare impacts
- Nanoparticles: synthesis and applications
- Indoor Air Quality and Microbial Exposure
- Respiratory viral infections research
- Influenza Virus Research Studies
- Climate Change and Health Impacts
- Inhalation and Respiratory Drug Delivery
- Noise Effects and Management
- COVID-19 impact on air quality
- Healthcare and Environmental Waste Management
- COVID-19 and Mental Health
- Infection Control in Healthcare
- Microplastics and Plastic Pollution
- Building Energy and Comfort Optimization
- Bacteriophages and microbial interactions
- SARS-CoV-2 detection and testing
- Toxic Organic Pollutants Impact
- Effects and risks of endocrine disrupting chemicals
- COVID-19 Pandemic Impacts
Virginia Tech
2016-2025
ORCID
2024
Environment and Climate Change Canada
2023
National Sun Yat-sen University
2021
Museum of Heilongjiang Province
2021
The University of Melbourne
2020
Austin Health
2020
Peninsula Health
2020
Eastern Health
2016-2020
Monash Health
2016-2020
During the 2020 COVID-19 pandemic, an outbreak occurred following attendance of a symptomatic index case at weekly rehearsal on 10 March Skagit Valley Chorale (SVC). After that rehearsal, 53 members SVC among 61 in were confirmed or strongly suspected to have contracted and two died. Transmission by aerosol route is likely; it appears unlikely either fomite ballistic droplet transmission could explain substantial fraction cases. It vital identify features cases such as this better understand...
Motor vehicles are a significant source of polycyclic aromatic hydrocarbon (PAH) emissions. Improved understanding the relationship between fuel composition and PAH emissions is needed to determine whether reformulation viable approach for reducing concentrations were quantified in gasoline diesel samples collected summer 1997 northern California. Naphthalene was predominant both fuels, with up 2600 mg L-1 1600 fuel. Particle-phase size distributions exhaust emission factors measured two...
Abstract. An Aerodyne Aerosol Mass Spectrometer (AMS) was deployed at the CENICA Supersite, during Mexico City Metropolitan Area field study (MCMA-2003) from 31 March-4 May 2003 to investigate particle concentrations, sources, and processes. The AMS provides real time information on mass concentration composition of non-refractory species in particulate matter less than 1 µm (NR-PM1) with high size-resolution. In order account for refractory material aerosol, we also present estimates Black...
Influenza incidence and seasonality, along with virus survival transmission, appear to depend at least partly on humidity, recent studies have suggested that absolute humidity (AH) is more important than relative (RH) in modulating observed patterns. In this perspective article, we re-evaluate of influenza aerosols, transmission animal models show the combination temperature RH equally valid as AH a predictor. Collinearity must be considered, higher levels are only possible temperatures,...
Each day people are exposed to millions of bioaerosols, including whole microorganisms, which can have both beneficial and detrimental effects. The next chapter in understanding the airborne microbiome built environment is characterizing various sources microorganisms relative contribution each. We identified following eight major categories bacteria, viruses, fungi environment: humans; pets; plants; plumbing systems; heating, ventilation, air-conditioning mold; dust resuspension; outdoor...
The detailed physico-chemical characteristics of respiratory droplets in ambient air, where they are subject to evaporation, poorly understood. Changes the concentration and phase major components a droplet—salt (NaCl), protein (mucin) surfactant (dipalmitoylphosphatidylcholine)—may affect viability any pathogens contained within it thus may efficiency transmission infectious disease by aerosols. objective this study is investigate effect relative humidity (RH) on evaporating model fluids....
An inter-comparison study of instruments designed to measure the microphysical and optical properties soot particles was completed. The following mass-based were tested: Couette Centrifugal Particle Mass Analyzer (CPMA), Time-of-Flight Aerosol Spectrometer—Scanning Mobility Sizer (AMS-SMPS), Single Soot Photometer (SP2), Particle-Aerosol Spectrometer (SP-AMS) Photoelectric Sensor (PAS2000CE). Optical measured absorption (photoacoustic, interferometric, filter-based), scattering (in situ),...
Humidity has been associated with influenza's seasonality, but the mechanisms underlying relationship remain unclear. There is no consistent explanation for transmission patterns that applies to both temperate and tropical regions. This study aimed determine between ambient humidity viability of influenza A virus (IAV) during hosts explain it. We measured IAV in droplets consisting various model media, chosen isolate effects salts proteins found respiratory fluid, human mucus, at relative...
There is mounting evidence that the aerosol transmission route plays a significant role in spread of influenza temperate regions and efficiency this depends on humidity. Nevertheless, precise mechanisms by which humidity might influence transmissibility via have not been elucidated. We hypothesize airborne concentrations infectious A viruses (IAVs) vary with through its virus inactivation rate respiratory droplet size. To gain insight into transmission, we modeled size distribution dynamics...
The relative importance of the aerosol transmission route for influenza remains contentious. To determine potential to spread via route, we measured size distribution airborne A viruses. We collected size-segregated samples during 2009–2010 flu season in a health centre, day-care facility and onboard aeroplanes. Filter extracts were analysed using quantitative reverse transcriptase polymerase chain reaction. Half 16 positive, their total virus concentrations ranged from 5800 37 000 genome...
Building ventilation systems must get much better
The transmission of some infectious diseases requires that pathogens can survive (i.e., remain infectious) in the environment, outside host. Relative humidity (RH) is known to affect survival microorganisms environment; however, mechanism underlying relationship has not been explained, particularly for viruses. We investigated effects RH on viability bacteria and viruses both suspended aerosols stationary droplets using traditional culture-based approaches. Results showed generally decreased...
Ambient temperature and humidity strongly affect inactivation rates of enveloped viruses, but a mechanistic, quantitative theory these effects has been elusive. We measure the stability SARS-CoV-2 on an inert surface at nine conditions develop mechanistic model to explain predict how alter virus inactivation. find survives longest low temperatures extreme relative humidities (RH); median estimated half-life is >24 hr 10°C 40% RH, ∼1.5 27°C 65% RH. Our uses fundamental chemistry why rate...
Infectious diseases caused by enveloped viruses, such as influenza, severe acute respiratory syndrome (SARS), and Middle East (MERS), cause thousands of deaths billions dollars economic losses per year. Studies have found a relationship among temperature, humidity, influenza virus incidence, transmission, or survival; however, there are contradictory claims about whether absolute humidity (AH) relative (RH) is most important in mediating infectivity. Using the bacteriophage Phi6, which has...
Pandemic and seasonal influenza viruses can be transmitted through aerosols droplets, in which must remain stable infectious across a wide range of environmental conditions. Using humidity-controlled chambers, we studied the impact relative humidity on stability 2009 pandemic A(H1N1) virus suspended stationary droplets. Contrary to prevailing paradigm that modulates respiratory aerosols, found supplemented with material from apical surface differentiated primary human airway epithelial cells...
Significance Aerosols with high water content (aerosol droplets) are ubiquitous and play a significant role in atmospheric chemistry meteorology. However, directly measuring the pH of an individual aerosol droplet remains challenging due to its inaccessibility electrodes. In this study, nanometer-sized probes were dispersed droplets report via surface-enhanced Raman spectroscopy. The core exhibits higher than bulk solution, suggesting presence stable gradient. This situ technique extends...
Buildings represent habitats for microorganisms that can have direct or indirect effects on the quality of our living spaces, health, and well-being. Over last ten years, new research has employed sophisticated tools, including DNA sequencing-based approaches, to study microbes found in buildings overall built environment. These investigations catalyzed insights into questions about surround us daily lives. The emergence "microbiology environment" field required bridging disciplines,...
Abstract Background During a period of rapid growth in our understanding the microbiology built environment recent years, majority research has focused on bacteria and fungi. Viruses, while probably as numerous, have received less attention. In response, Alfred P. Sloan Foundation supported workshop entitled “Viruses Built Environment (VIBE),” at which experts environmental engineering, microbiology, epidemiology, infection prevention, fluid dynamics, occupational health, metagenomics,...
Covid-19 has redefined airborne transmissionImproving indoor ventilation and air quality will help us