Table 2.
Air pollutants (annual average concentrations) and their distributions
| Percentile | Pearson’s correlation coefficients | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Air pollutants | Mean | SD | IQR | 10th | 25th | 50th | 75th | 90th | PM10 | NO2 | SO2 | CO |
| PM10 (μg/m3) | 52.5 | 5.8 | 10 | 46 | 47 | 53 | 57 | 60 | 1 | 0.52*** | 0.40*** | 0.63*** |
| NO2 (ppb) | 25.2 | 6.9 | 12 | 16 | 19 | 24 | 31 | 34 | – | 1 | 0.16*** | 0.34*** |
| SO2 (ppb) | 5.5 | 1.1 | 1 | 4 | 5 | 5 | 6 | 7 | – | – | 1 | 0.28*** |
| CO (ppm) | 0.6 | 0.1 | 0.1 | 0.4 | 0.5 | 0.6 | 0.6 | 0.7 | – | – | – | 1 |
SD standard deviation, IQR interquartile range, PM10 particulate matter < 10 μm in diameter, NO2 nitrogen dioxide, SO2 sulfur dioxide, CO carbon monoxide
*p < 0.05, **p < 0.01, ***p < 0.001