Table 1a. Average of mean and maximum ambient PM2.5 concentration between 2017 and 2021.
Year Mean PM2.5 (± SD) (µg/m3) Mean of maximum PM 2.5 (± SD) (µg/m3) p-value
2017 23.3±13.8 39.8±25.3 <0.001*
2018 27.0±18.2 46.5±26.4
2019 32.0±23.2 62.6±54.3
2020 22.4±19.7 41.0±37.9
2021 28.9±24.9 49.6±41.2
Overall 48.1±39.0 48.1 ± 39.0

*p<0.001 both mean and maximum value.