Table 2 Correlations between different air pollutants and meteorological variables.

		SO2	NO2	PM10	O3	PM2.5	Temperature	Humidity
SO2	r	1.00	0.659*	0.229*	−0.037*	0.282	0.084*	0.169*
	p value	—	<0.001	<0.001	0.111	<0.001	<0.001	<0.001
NO2	r		1.00	0.399*	0.338*	0.441	−0.268*	0.212*
	p value		—	<0.001	<0.001	<0.001	<0.001	<0.001
PM10	r			1.00	0.421*	0.952	−0.344*	−0.390*
	p value			—	<0.001	<0.001	<0.001	<0.001
O3	r				1.00	0.394	−0.028	−0.106*
	p value				—	<0.001	0.236	<0.001
PM2.5	r					1.00	−0.356	−0.343
	p value					—	<0.001	<0.001
Temperature	r						1.00	0.127*
	p value						—	0.001
Humidity	r							1.00
	p value							—

r, Pearson correlation coefficient; SO₂, sulphur dioxide; NO₂, nitrogen dioxide; O₃, ozone; PM₁₀, PM_2.5, particulates with an aerodynamic diameter <10 μm or <2.5 μm.