Inhaled aerosols: Their role in COVID-19 transmission, including biophysical interactions in the lungs

Abstract

The high rate of spreading of COVID-19 is attributed to airborne particles exhaled by infected but often asymptomatic individuals. In this review the role of aerosols in SARS-CoV-2 coronavirus transmission is discussed from the bio-physical perspective. The essential properties of the coronavirus virus transported inside aerosol droplets, their successive inhalation, and size-dependent deposition in the respiratory system are highlighted. The importance of face covers (respirators and masks) in the reduction of aerosol spreading is analyzed. Finally, the discussion of the physicochemical phenomena upon coronavirus enter to surface of lung liquids (bronchial mucus and pulmonary surfactant) is presented with a focus on a possible role of interfacial phenomena in pulmonary alveoli. Information given in this review should be important in understanding the essential biophysical conditions of COVID-19 infection via aerosol route as a prerequisite for effective strategies of respiratory tract protection and, possibly, indications for future treatments of the disease.

Usefulness of facial masks against COVID-19 transmission – an experimental evidence

“…They have been tested using a manikin head adapted for fitting the masks and aerosol emission via either a mouth opening or nostrils (Fig. 1a) Aerosol particles in the close vicinity of the manikin head were counted with the OPC-N3 laser spectrometer (Alphasense, Great Britain) that allowed to monitor the concentration of particles within the size range of 0.35-40 m which is representative for aerosols expelled from the respiratory system [5]. First trials with the wet aerosol generated from a medical nebulizer were unsuccessful due to the partial evaporation of droplets that made the results vague.…”

“…Instead, most of the population wears less sophisticated face covers, e.g., surgical masks or cloth masks. Despite their lower filtration efficiency during inhalation, they may have good barrier properties against exhalation of the virus in the form of droplets generated in the respiratory system [5]. The aim of this work is to test this function under realistic in vitro conditions.…”

When do we need massive computations to perform detailed COVID-19 simulations?

“…The virus spreads through droplets that are released when an infected individual coughs or sneezes. As a respiratory disease, the primary mode of transmission is thus via exposure to droplets, either indirectly (e.g., via contact through contaminated objects or hands) or directly (air borne) [33,34] . The virus infects cells in an individual's lungs, interfering with the lungs' ability to function properly [35] .…”

Peptide‐Based Inhibitors for SARS‐CoV‐2 and SARS‐CoV

“…[ 13 , 14 ] In addition to viral spread in hospitals and care homes, which are prevalent among all three pandemic HCoV, a high incidence of asymptomatic and pre‐symptomatic [ 15 ] SARS‐CoV‐2 infection drastically increases community spread, as individuals transmit the virus before learning they are symptomatic (if they ever do). [ 16 , 17 , 18 , 19 ]…”