Table 2.

Mean and distribution of air pollutants in different seasons from 72 monitoring stations in Taiwan, 2001–2003.

Pollutant	Mean ± SD	Minimum	25th percentile	Median	75th percentile	Interquartile rangea	Maximum
O3 (ppb)
Spring	29.69 ± 6.06	16.30	25.47	28.90	32.97	7.50	50.27
Summer	23.56 ± 4.14	14.37	20.90	23.57	25.37	4.47	39.10
Fall	29.07 ± 5.42	15.87	25.80	28.93	32.07	6.27	42.80
Winter	26.92 ± 5.57	17.60	22.80	26.27	30.83	8.03	48.13
Average	27.31 ± 4.88	16.70	24.43	26.78	30.11	5.68	45.08
CO (pphm)
Spring	71 ± 37	27	51	64	80	29	247
Summer	60 ± 40	23	41	50	66	25	256
Fall	65 ± 42	26	46	57	71	25	306
Winter	78 ± 42	25	53	71	88	35	298
Average	69 ± 40	25	48	62	76	28	277
NOx (ppb)
Spring	21.97 ± 8.17	1.23	17.43	21.72	26.27	8.84	49.68
Summer	15.89 ± 6.86	0.95	11.54	14.47	19.08	7.54	41.58
Fall	17.60 ± 6.53	0.83	13.68	17.49	21.25	7.57	39.93
Winter	25.33 ± 8.88	1.08	19.23	25.70	30.87	11.64	48.38
Average	20.20 ± 7.24	1.02	16.03	20.16	23.94	7.91	44.20
SO2 (ppb)
Spring	4.22 ± 2.59	0.23	2.53	3.67	5.18	2.64	12.63
Summer	3.35 ± 2.00	0.20	1.96	2.98	4.23	2.27	10.02
Fall	3.41 ± 2.07	0.20	2.00	2.83	4.54	2.54	11.07
Winter	4.88 ± 3.71	0.20	2.96	3.95	5.38	2.42	17.93
Average	3.96 ± 2.36	0.21	2.36	3.42	5.01	2.65	11.48
PM10 (μg/m3)
Spring	64.44 ± 16.21	23.33	53.00	67.00	75.42	22.42	94.33
Summer	39.11 ± 8.31	17.33	33.92	39.67	43.42	9.50	60.00
Fall	47.76 ± 11.77	21.00	39.33	49.17	55.66	16.33	72.00
Winter	68.00 ± 21.88	21.33	50.25	67.17	84.67	34.42	116.0
Average	54.83 ± 13.07	20.75	44.81	57.17	64.54	19.73	78.05

^aRange from 25th to 75th percentile of site-specific concentrations.