Table 1.
Model parameters and ranges applied to compute infection risk. Standard setting refers to a classroom (indoor environment nr. 2 in Table 2). The spreadsheet is available in the Supplementary Material and additionally online: https://www.mpic.de/4747065/risk-calculation.
| Parameters | Standard | Range | Units |
|---|---|---|---|
| Infectious episode (exposure) | 2 | 0.08–5 | Days |
| Wet aerosol diameter | 5 | 2–10 | µm |
| Virus lifetime in aerosol | 1.7 | 0.6–2.6 | Hours |
| Concentration from breathing | 0.1 | 0.06–1.0 | cm−3 |
| Concentration from speaking (singing) | 1.1 | 0.06–6.0 | cm−3 |
| Speaking/breathing ratio | 0.10 | 0–1 | - |
| Respiratory rate | 10 | 5–20 | L/min |
| Viral load “highly infectious” | 5 × 108 | 108–109 | RNA Copies/cm3 |
| Viral load “super infectious” | 5 × 109 | 109–1010 | RNA copies/cm3 |
| Deposition probability in lungs | 0.5 | 0.2–0.8 | - |
| Infective dose (D50) | 316 | 100–1000 | RNA copies |
| Room area | 60 | 40–100 | m2 |
| Room height | 3 | 3–4 | m |
| Subjects in room | 25 | 4–100 | Persons |
| Passive ventilation rate | 0.35 | 0–1 | Hour−1 |
| Active ventilation rate (with outside air) | 2 | 2–9 | Hour−1 |
| Face mask filter efficiency from inhalation plus exhalation | 0.7 | 0–0.95 | - |