Table 1.
Overview of the Parameter Values.
| Input Parameter Values | Sensitivity Analysis Values | ||||||
|---|---|---|---|---|---|---|---|
| Parameter | Description | Low Risk | Intermediate Risk | High Risk | Lower Limit (–75%) | Upper Limit (+75%) |
Sources |
| R | Mask protection factor, % | 85 | 24 | 0 | 6 | 42 | Skaria and Smaldone 2014 |
| t | Time in hour | 1 | 1 | 1 | 0.25 | 1.75 | |
| C | Indoor CO2, ppm | 774 | 1,135 | 2,375 | 283.75 | 1,986 | Helmis et al. 2007 |
| Co | Outdoor CO2, ppm | 400 | 400 | 400 | ASHRAE 2016 | ||
| Ca | Fraction of CO2 in exhaled breath, ppm | 37,500 | 37,500 | 37,500 | Rudnick and Milton 2003 | ||
| f | Fraction of indoor air that is exhaled breath | 0.009973 | 0.0196 | 0.05264 | Rudnick and Milton 2003 | ||
| qm | Quanta for measles virus | 106 | 124 | 480 | 31 | 217 | Riley et al. 1978; Chen et al. 2006; Liao et al. 2008 |
| qs | Quanta for SARS coronavirus | 11.4 | 28.94 | 295.5 | 7.23 | 50.65 | Liao et al. 2008; Qian et al. 2009 |
| qi | Quanta for influenza virus | 15 | 76.18 | 128 | 19 | 133.32 | Rudnick and Milton 2003; Chen and Liao 2008; Liao et al. 2008 |
| qt | Quanta for Mycobacterium tuberculosis | 1.27 | 8.2 | 12.7 | 2.05 | 14.35 | Escombe et al. 2007; Nardell 2015 |
| ql | Quanta for Legionella pneumophila | 5.45 | 8.39 | 11.32 | 2.1 | 14.68 | Armstrong and Haas 2007; Dutil et al. 2007 |
CO2, carbon dioxide; ppm, parts per million; SARS, severe acute respiratory syndrome.