Table 2. Mean concentration (μg/m³) of main compositions detected in PM_2.5 sample.

	Component	Concentration	Component	Concentration
Carbon	organic carbon	58.36	elemental carbon	10.84
Water soluble ion	Na+	1.72	NH4+	29.15
	K+	6.51	NO3−	46.04
	Ca2+	3.78	SO42−	47.90
	Mg2+	0.68	Cl−	10.60
Metal element	Na	1.92	Ni	11.36 × 10−3
	Mg	0.98	Cu	141.08 × 10−3
	Al	1.42	Zn	1.74
	Ca	4.12	As	65.18 × 10−3
	V	7.56 × 10−3	Se	14.64 × 10−3
	Cr	6.10 × 10−3	Mo	6.22 × 10−3
	Mn	0.46 × 10−3	Pb	0.54
	Fe	1.52 × 10−3	Cd	7.12 × 10−3
	Co	4.48 × 10−3
Polycyclic Aromatic Hydrocarbons (PAH)	naphthalene	2.15 × 10−3	chrysene	22.65 × 10−3
	acenaphthylene	0.53 × 10−3	Benzo [a] anthracene	15.13 × 10−3
	acenaphthene	0.70 × 10−3	Benzo [b] fluoranthene	30.26 × 10−3
	fluorene	0.98 × 10−3	Benzo [k] fluoranthene	3.25 × 10−3
	phenanthrene	18.26 × 10−3	Benzo [a] pyrene	6.45 × 10−3
	anthracene	1.60 × 10-3	Diphenyl [a,h] anthracene	3.82 × 10−3
	fluoranthene	67.38 × 10−3	Indene [g, h, I] pyrene	10.57 × 10−3
	pyrene	31.61 × 10−3	Indene [1, 2, 3 -c, d] pyrene	10.92 × 10−3