Table 2.
Descriptive statistics of the air pollutants, AQI, and meteorological factors in the BMR during the COVID-19 outbreak between Jan 1st and Mar 30th in 2020.
| Parameter | Bangkok Metropolitan Region (BMR) |
|||
|---|---|---|---|---|
| COVID-19 outbreak (2020) | The same period of the previous year (2019) | Mean difference (95% CI) | % Difference | |
| Ambient air parameters | ||||
| CO (μg/m3) | 660.21 | 536.74 | 123.47 (43.59, 203.34) | +23.00** |
| NO (μg/m3) | 3.29 | 6.03 | – 2.74 (– 5.09, −0.39) | – 45.44** |
| NO2 (μg/m3) | 29.07 | 20.91 | 8.15 (3.52, 12.79) | +39.02** |
| SO2 (μg/m3) | 3.81 | 2.68 | 1.13 (0.30, 1.97) | +42.16** |
| O3 (μg/m3) | 54.97 | 54.96 | 0.01 (– 4.63, 4.65) | +0.02 |
| PM10 (μg/m3) | 51.70 | 50.11 | 1.59 (– 4.90, 8.08) | +3.17 |
| PM2.5 (μg/m3) | 32.19 | 27.18 | 5.01(– 0.38, 9.65) | +18.43* |
| Air quality index (AQI) | 55.91 | 63.22 | – 7.31(– 16.67, 2.05) | – 11.56 |
| Meteorological | ||||
| Temperature (°C) | 28.90 | 28.58 | 0.32 (0.11, 0.54) | +1.12** |
| Relative humidity (%) | 70.44 | 72.23 | – 1.79 (– 4.81, 1.22) | – 2.48 |
| Absolute humidity (g/m3) | 19.50 | 20.00 | – 0.50 (– 1.33, 0.33) | – 2.50 |
| Wind speed (m/s) | 1.77 | 1.77 | 0.01 (– 0.14, 0.12) | 0.00 |
| Rainfall (mm) | 0.00 | 0.04 | – 0.04 (– 0.10, 0.03) | – 100.00 |
* Statistically significant at p < 0.05.
** Statistically significant at p < 0.01.
+ Air pollutants, AQI, and meteorological parameters increased as the percentage of the difference increased.
– Air pollutants, AQI, and meteorological parameters decreased percent differences.