TABLE I.
Aerosol concentrations and persistence times in different public spaces characterized by the number of people present, volume, and rate of ventilation. In all but the club scenario where aerosols were artificially generated, the aerosol origin is from speaking, coughing, and sneezing of the people. Spaces were sampled, which gave us permission to do so—these were mainly well-ventilated spaces in modern buildings. Each space was typically sampled in five different places. Estimated viral load based on calculations.
| Air change per | 50% decrease | Covid-19 infection | |||||
|---|---|---|---|---|---|---|---|
| Space | Size (m3) | hour (h−1) | Aerosol origin | (min) | Aerosol part/l | RNA copies/l | risk |
| Gym | 2 000 | 5–15 | 25 visitors | 1 | <10 | <1 | Low |
| Train | 150 | 0–5 | 20 visitors | 2 | 210 | <21 | Low |
| Meeting room | 30 | 10 | 4 visitors | 1 | 45 | <5 | Low |
| Night club | 2 000 | 5–15 | Artificial | 1 | <10 | <1 | Low |
| Car | 3 | 5–20 | 2 visitors | 0.5 | 20 | <2 | Low |
| Airport | 12 000 | 5–15 | ∼100 visitors | 1 | <10 | <1 | Low |
| Restaurant | 120 | 8 | 25 visitors | 1 | 248 | <25 | Low |
| Restroom | 8 | ∼1 | 1 visitor | 4 | 7716 | <772 | Intermediate |
| Office space | 50 | 10 | 5 visitors | 1 | 35 | <4 | Low |
| Unventilated living room | 80 | ∼1 | 4 visitors | 5 | 5214 | <520 | Intermediate |
| Elevator | 8 | ∼1 to 4 | 2 visitors | 5 | 4350 | <435 | Intermediate |