Table 2.

Correlation coefficients between PM_2.5 and chemical components.

OC	EC	Cl	NO3	SO4	Na	NH4	K	Mg	Ca
PM2.5		0.91		0.85		0.45		0.90		0.89		–0.06		0.94		0.63		–0.05		–0.06
OC				0.91		0.57		0.81		0.75		0.01		0.81		0.69		–0.02		–0.06
EC						0.58		0.76		0.70		0.00		0.76		0.65		–0.01		–0.04
Cl								0.51		0.23		–0.04		0.39		0.69		–0.11		–0.21
NO3										0.72		–0.07		0.89		0.60		–0.13		–0.11
SO4												–0.01		0.94		0.46		–0.01		–0.08
Na														–0.07		0.13		–0.01		0.06
NH4																0.53		–0.07		–0.15
K																		–0.18		–0.16
Mg																				0.37