Table 3.

Summary statistics and Spearman correlations of 2-year mean air pollutants

	Summary statistics					Spearman correlation coefficients
	Mean	Median	Minimum	Maximum	IQR	PM2.5	PM10	SO2	NO2	O3
PM2.5 (μg/m3)	37.17	38.30	27.99	46.96	8.84	1.00	0.71*	0.52*	0.60*	-0.49*
PM10 (μg/m3)	55.43	55.09	42.17	67.33	7.58		1.00	0.63*	0.75*	-0.51*
SO2 (μg/m3)	16.12	15.92	9.31	22.28	5.44			1.00	0.37*	-0.35*
NO2 (μg/m3)	25.98	23.07	7.94	62.68	18.07				1.00	-0.68*
O3 (μg/m3)	56.23	56.96	40.54	68.83	7.38					1.00

PM_2.5 Particulate matter ≤ 2.5 µm, PM₁₀ Particulate matter < 10 µm, SO₂ Sulfur dioxide, NO₂ Nitrogen dioxide, O₃ Ozone

Note: Spearman correlation coefficients, ^*:P < 0.05