Table 2. Descriptive statistics of air pollutants and weather conditions.

	P25	P50	P75	Minimum	Maximum	Mean (SD)
Air pollutant concentrations, µg/m3
PM2.5	32.25	66.50	114.55	5.20	392.60	84.54 (69.01)
PM10	74.28	116.60	182.82	8.90	448.60	116.38 (74.67)
SO2	5.20	11.00	26.90	2.00	133.10	20.56 (23.33)
NO2	38.65	49.40	67.50	8.10	135.90	54.69 (23.79)
CO	646.30	996.20	1574.10	222.10	5229.80	1266.70 (875.26)
O3	13.78	28.35	47.40	2.60	188.00	56.24 (37.94)
Meteorological factors
Temperature, °C	2.50	14.00	23.00	−7.00	31.00	13.36 (10.94)
Relative humidity, %	37.00	50.00	65.00	8.00	93.00	50.75 (19.08)

SD, standard deviation.