Table 1.
Classification of Ventilation Risk Status in Classrooms and Clinic Rooms
| Setting | Total Duration of Sampling, h | Duration with Ambient CO2 ⩾ 1,000 ppm, h (% of Total Duration) | Proportion of Rooms with Median CO2 ⩾ 1,000 ppm, n/N (%) | Proportion of Rooms with Peak CO2 ⩾ 1,000 ppm, n/N (%) | Proportion of Rebreathed Air, Median (IQR) |
|---|---|---|---|---|---|
| School A | 24.4 | 9.5 (38.9%) | 14/31 (45.2%) | 19/31 (61.3%) | 1.26% (1.15–2.42) |
| School B | 17.4 | 6.2 (35.6%) | 11/32 (34.4%) | 20/32 (62.5%) | 1.40% (1.02–1.81) |
| All schools | 41.8 | 15.7 (37.6%) | 25/63 (39.7%) | 39/63 (61.9%) | 1.30% (1.06–2.28) |
| Clinic A | 22.0 | 0 (0%) | 0/9 (0%) | 0/9 (0%) | 0.03% (0.02–0.10) |
| Clinic B | 14.3 | 0.15 (1.0%) | 0/7 (0%) | 3/7 (42.9%) | 0.58% (0.47–0.63) |
| Clinic C | 8.7 | 0 (0%) | 0/5 (0%) | 0/5 (0%) | 0.43% (0.33–0.52) |
| All clinics | 45 | 0.15 (0.3%) | 0/21 (0%) | 3/21 (14.3%) | 0.33% (0.04–0.52) |
| Open air | 1.1 | 0 (0%) | 0/3 (0%) | 0/3 (0%) | NA |
Definition of abbreviations: IQR = interquartile range; NA = not applicable.