Table 2. Pearson correlation coefficients for meteorologic and air pollution variables in Shanghai, 2001–2004.

	DTR	Mean temperature	Relative humidity	PM10	SO2	NO2	O3
DTR	1	0.13	−0.47	0.42	0.41	0.36	0.49
Mean temperature		1	0.21	−0.21	−0.20	−0.38	0.41
Relative humidity			1	−0.37	−0.52	−0.27	−0.36
PM10				1	0.63	0.70	0.19
SO2					1	0.73	0.17
NO2						1	0.06
O3							1

Abbreviations: DTR, diurnal temperature range; PM₁₀, particulate matter <10 μm in diameter; SO₂, sulfur dioxide; NO₂, nitrogen dioxide; O₃, ozone.