RE: "Here, we develop a quantitative model of airborne virus

Posted on: May 21, 2021 at 12:30:19 CT

we investigated characteristic virus distributions in both exhaled air samples and indoor air samples including coronaviruses (HCoV-NL63, -OC43, -229E and -HKU1), influenza viruses (A and B), rhinoviruses and SARS-CoV-2 (supplementary text, section S1). We find that usually just a minor fraction of exhaled respiratory particles contains viruses. In contrast to the high number of emitted respiratory particles, the number of viruses in 30-min samples of exhaled air (Nv,30,ex) are typically low with mean values around ~53 for coronaviruses (HCoV-NL63, -OC43, -229E and -HKU1), ~38 for influenza viruses (A and B), and ~96 for rhinoviruses (11) (supplementary text, section S1.2, and Fig. 2). Figure 2, A and B, shows the infection probabilities obtained by inserting the number of exhaled viruses (Nv,30,ex) for the number of potentially inhaled viruses (Nv,30) assuming a characteristic infectious dose of IDv,50 = 100 or 1000, respectively (12–14). For SARS-CoV-2 in various medical centers, we obtained mean values of Nv,30 in the range of ~1 to ~600 (15–18) (supplementary text, section S1.3), which correspond to Pinf values in the range of ~0.1% to 10% for IDv,50 = 1000 and ~1% to 100% for IDv,50 = 100. The wide range of Nv,30/ IDv,50 and Pinf values demonstrate that both virus-limited and virus-rich conditions can occur in indoor environments.