Allen E. Haddrell
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Measurements of Surrogate Respiratory Sessile Droplet pH and Implications for Exhaled Respiratory Aerosol and Airborne Disease Transmission Open
Respiratory aerosol pH has been proposed as a key factor driving the infectivity loss of SARS-CoV-2 viruses and influenza A virus in exhaled aerosols, thus affecting the airborne transmission of respiratory diseases. Sodium bicarbonate act…
Studies of the Crystallization and Dissolution of Individual Suspended Sodium Chloride Aerosol Particles Open
Aerosols transform between physical phases, as they respond to variations in environmental conditions. There are many industries that depend on these dynamic processes of crystallization and dissolution. Here, a single particle technique (…
Ambient carbon dioxide concentration correlates with SARS-CoV-2 aerostability and infection risk Open
An improved understanding of the underlying physicochemical properties of respiratory aerosol that influence viral infectivity may open new avenues to mitigate the transmission of respiratory diseases such as COVID-19. Previous studies hav…
Inactivation Mechanisms of Escherichia coli in Simulants of Respiratory and Environmental Aerosol Droplets Open
The airborne transmission of disease relies on the ability of microbes to survive aerosol transport and, subsequently, cause infection when interacting with a host. The length of time airborne microorganisms remain infectious in aerosol dr…
Novel instrument to measure water uptake, dissolution and hygroscopic growth of an individual levitated aerosol particle in an environment identical to the lung (relative humidity >99.5%) Open
Dry powder inhalers (DPIs) are commonly used devices for delivering inhalable pharmaceuticals. The overall efficacy of any inhalable pharmaceutical is a function of total and regional dose, and the bioavailability of the active pharmaceuti…
The microphysics of surrogates of exhaled aerosols from the upper respiratory tract Open
Airborne transmission plays a significant role in the transmission of respiratory diseases such as COVID-19, for which the respiratory aerosol droplets are responsible for the transportation of potentially infectious pathogens. However, th…
An assessment of the airborne longevity of group A Streptococcus Open
Graphical abstract
Ambient Carbon Dioxide Concentration Correlates with SARS-CoV-2 Aerostability and Infection Risk Open
An improved understanding of the underlying physicochemical properties of respiratory aerosol that influence viral infectivity may open new avenues to mitigate the transmission of respiratory diseases such as COVID-19. Previous studies hav…
View article: Differences in airborne stability of SARS-CoV-2 variants of concern is impacted by alkalinity of surrogates of respiratory aerosol
Differences in airborne stability of SARS-CoV-2 variants of concern is impacted by alkalinity of surrogates of respiratory aerosol Open
The mechanistic factors hypothesized to be key drivers for the loss of infectivity of viruses in the aerosol phase often remain speculative. Using a next-generation bioaerosol technology, we report measurements of the aero-stability of sev…
Oxidative Stress Contributes to Bacterial Airborne Loss of Viability Open
The airborne transport of bacteria has a wide range of impacts, from disease transmission to cloud formation. By understanding the factors that influence the airborne stability of bacteria, we can better understand these processes.
How to engineer aerosol particle properties and biopharmaceutical performance of propellant inhalers Open
Given the environmental compulsion to reformulate pressurised metered dose inhalers (pMDI) using new propellants with lower global warming potential, this study investigated how non-volatile excipients can be used to engineer aerosol parti…
Mucin Transiently Sustains Coronavirus Infectivity through Heterogenous Changes in Phase Morphology of Evaporating Aerosol Open
Respiratory pathogens can be spread though the transmission of aerosolised expiratory secretions in the form of droplets or particulates. Understanding the fundamental aerosol parameters that govern how such pathogens survive whilst airbor…
The dynamics of SARS-CoV-2 infectivity with changes in aerosol microenvironment Open
Understanding the factors that influence the airborne survival of viruses such as severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in aerosols is important for identifying routes of transmission and the value of various mitigat…
The Dynamics of SARS-CoV-2 Infectivity with Changes in Aerosol Microenvironment Open
Understanding the factors that influence the airborne survival of viruses such as SARS-CoV-2 in aerosols is important for identifying routes of transmission and the value of various mitigation strategies for preventing transmission. We pre…
View article: Analytical challenges when sampling and characterising exhaled aerosol
Analytical challenges when sampling and characterising exhaled aerosol Open
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 generated as well as their size distribut…
Measuring stability of virus in aerosols under varying environmental conditions Open
Copyright © 2021 American Association for Aerosol Research
Aerosol and droplet generation from performing with woodwind and brass instruments Open
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 generated when playing woodwind and brass…
Water Uptake by Evaporating pMDI Aerosol Prior to Inhalation Affects Both Regional and Total Deposition in the Respiratory System Open
As pulmonary drug deposition is a function of aerosol particle size distribution, it is critical that the dynamics of particle formation and maturation in pMDI sprays in the interim between generation and inhalation are fully understood. T…
View article: Comparing aerosol concentrations and particle size distributions generated by singing, speaking and breathing
Comparing aerosol concentrations and particle size distributions generated by singing, speaking and breathing Open
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. Restrictions on musical performan…
Transformative Approach To Investigate the Microphysical Factors Influencing Airborne Transmission of Pathogens Open
A transformative approach to identify the physicochemical processes that impact the biological decay rates of bacteria in aerosol droplets is described. It is shown that the evaporation process and changes in the phase and morphology of th…
Data from Bioaerosol Longevity (10-2020) Open
The airborne transmission of infection relies on the ability of pathogens to survive aerosol transport as they transit between hosts. Understanding the parameters that determine the survival of airborne microorganisms is critical to mitiga…
Laboratory study of bioaerosols: Traditional test systems, modern approaches, and environmental control Open
Biological aerosol particles have been studied in the laboratory for many decades to understand their roles in human health and disease and in environmental processes. These studies have used a variety of instrumentation under varying cond…
Identifying time-dependent changes in the morphology of an individual aerosol particle from its light scattering pattern Open
The physical, chemical, and biological properties of an aerosol droplet/particle are dependent on the morphology of the droplet/particle itself; for example, a liquid droplet will be processed by oxidants in the gas phase in a fundamentall…
Assessing the airborne survival of bacteria in populations of aerosol droplets with a novel technology Open
The airborne transmission of infection relies on the ability of pathogens to survive aerosol transport as they transit between hosts. Understanding the parameters that determine the survival of airborne microorganisms is critical to mitiga…
Studies of competing evaporation rates of multiple volatile components from a single binary-component aerosol droplet Open
The simultaneous evaporation and condensation of multiple volatile components from multicomponent aerosol droplets leads to changes in droplet size, composition and temperature.
Data from Identifying time-dependent changes in the morphology of an individual aerosol particle from their light scattering patterns (08-2019) Open
The physical, chemical, and biological properties of an aerosol droplet/particle are dependent on the morphology of the droplet/particle itself; for example, a liquid droplet will be processed by oxidants in the gas phase in a fundamentall…
Data for PCCP (2018) paper "Amorphous Phase State Diagrams and Viscosity of Ternary Aqueous Organic/Organic and Inorganic/Organic Mixtures" Open
A Dimer Collision, Isolation and Coalescence (DCIC) technique is used to probe the phase behaviour and glass transition temperatures of ternary aerosol mixtures. The DCI technique is used to perform temperature and relative humidity depend…
Supplementary material from "Assessing the airborne survival of bacteria in populations of aerosol droplets with a novel technology" Open
The airborne transmission of infection relies on the ability of pathogens to survive aerosol transport as they transit between hosts. Understanding the parameters that determine the survival of airborne microorganisms is critical to mitiga…