Table 3.
Average PM2.5 concentration during different phases of study and its comparison with matching business as usual (BAU) period along with percentage change in concentration of PM2.5 (μg m−3) in five Indian megacities
| Chennai | Hyderabad | Kolkata | Mumbai | New Delhi | |
|---|---|---|---|---|---|
| Average PM2.5 concentration (μg m−3) in Pre-Lock down (PLDN) | 21.8 ± 10.0 | 34.3 ± 10.9 | 65.1 ± 30.1 | 48.6 ± 20.6 | 60.0 ± 18.4 |
| Average PM2.5 concentration (μg m−3) in BAU-PM (PLDN matching period) | 22.4 ± 4.5 | 58.5 ± 7.6 | 76.0 ± 9.4 | 68.8 ± 24.4 | 80.1 ± 18.2 |
| Percentage change in PLDN from BAU-PM (%) | − 2.6 | − 41.3 | − 14.3 | −29.3 | − 25.1 |
| Average PM2.5 concentration (μg m−3) Lockdown (LDN) | 14.4 ± 8.7 | 30.9 ± 8.1 | 24.7 ± 13.7 | 24.6 ± 9.7 | 44.2 ± 16.3 |
| Average PM2.5 concentration (μg m−3) in BAU-LM (LDN matching period) | 20.3 ± 4.8 | 50.9 ± 7.8 | 39.7 ± 7.3 | 33.0 ± 13.6 | 79.4 ± 21.0 |
| Percentage change in LDN from BAU-LM (%) | − 29.0 | − 39.3 | − 37.7 | − 25.3 | − 44.3 |
| Average PM2.5 concentration (μg m−3) in Unlock (ULC) | 17.5 ± 5.8 | 11.8 ± 5.0 | 13.2 ± 8.2 | 12.5 ± 6.1 | 31.1 ± 13.4 |
| Average PM2.5 concentration (μg m−3) in BAU-UM (ULC matching period) | 25.8 ± 3.7 | 25.4 ± 5.9 | 29.7 ± 6.4 | 24.8 ± 6.8 | 41.7 ± 14.0 |
| Percentage change in ULC from BAU-UM (%) | − 32.1 | − 53.5 | − 55.7 | − 49.8 | − 25.3 |