Thread by @AliNouriPhD

1/📌SARS-CoV-2 in aerosols: from dispersion in air, to inhalation and disease: (a) while large drops (green) are ballistically and fall, smaller ones (red) can remain buoyant; (b) Droplets evaporate to form aerosols, reducing to just biopolymers and virus particles🧵

2/Larger aerosols deposit in upper throat, nose, & tracheobronchial region of the lung. Medium-sized aerosols mostly deposit in small airways further down. The really small aerosols <1 μm can penetrate all the way to the alveoli - the basic units for gas exchange.

3/In contrast to other mode of transmission where virus hits nasal cavity and then finds its way into lungs, aerosols can directly reach alveolar region and attack alveolar cells that produce Pulmonary Surfactant. PS is needed to lower surface tension & prevent alveoli collapse

4/Loss of these alveolar cells results in alveolar instability, lung flooding, and respiratory failure - Acute Respiratory Distress Syndrome (ARDS). ARDS causes further damage through a hyperactive immune response of neutrophils and cytokines that damage alveoli even more.

5/Viewing transmission through the lens of bioaerosol mechanics highlights the need for mitigation approaches such as ventilation and other measures, and new therapeutic interventions, like surfactant therapy to alleviate ARDS symptoms.
pubs.acs.org/doi/10.1021/ac…