Machine learning to relate PM2.5 and PM10 concentrations to outpatient visits for upper respiratory tract infections in Taiwan: A nationwide analysis

Table 1 Nationwide and regional average particulate matter concentrations between December 2008 and December 2016 and the number of outpatient visits for upper respiratory infections in each season in Taiwan from January 2009 to December 2016

Regions/PM (µg/m3)		Spring	Summer	Fall	Winter
Taiwan	PM2.5	30.90 ± 12.30	17.97 ± 6.37	28.00 ± 10.20	34.44 ± 13.10
	PM10	58.05 ± 27.47	35.00 ± 7.74	53.96 ± 17.46	62.43 ± 21.31
Northern region	PM2.5	27.37 ± 12.43	18.63 ± 7.43	20.36 ± 10.02	25.95 ± 13.78
	PM10	49.52 ± 33.52	33.30 ± 11.64	38.63 ± 18.51	46.44 ± 24.17
Central region	PM2.5	35.36 ± 16.13	20.12 ± 9.37	32.99 ± 13.90	36.37 ± 15.64
	PM10	60.55 ± 30.03	35.64 ± 11.56	57.15 ± 20.32	60.30 ± 23.70
Southern region	PM2.5	34.99 ± 17.46	17.32 ± 8.71	37.33 ± 15.42	49.14 ± 15.95
	PM10	66.75 ± 32.10	36.51 ± 11.21	70.60 ± 25.93	87.42 ± 24.73
Eastern region	PM2.5	15.37 ± 8.05	10.36 ± 4.94	13.49 ± 7.82	15.62 ± 8.73
	PM10	30.49 ± 15.45	24.04 ± 9.86	31.85 ± 23.11	30.12 ± 14.67
Regions/URI patients (× 103)
Taiwan	Overall	523.75 ± 93.61	375.67 ± 35.07	492.46 ± 63.48	607.31 ± 124.83
	Elderly	70.13 ± 11.27	50.62 ± 4.75	60.98 ± 6.91	77.52 ± 17.23
Northern region	Overall	210.90 ± 35.83	148.45 ± 14.46	192.93 ± 26.09	238.55 ± 53.95
	Elderly	25.10 ± 3.99	17.73 ± 1.65	20.93 ± 2.55	27.19 ± 6.71
Central region	Overall	102.77 ± 20.04	72.74 ± 7.30	97.90 ± 12.79	121.29 ± 24.65
	Elderly	13.53 ± 2.23	9.63 ± 0.94	11.85 ± 1.36	14.88 ± 3.27
Southern region	Overall	77.95 ± 14.09	62.25 ± 7.06	78.97 ± 10.53	95.38 ± 18.11
	Elderly	11.78 ± 1.91	9.57 ± 1.17	11.29 ± 1.33	13.74 ± 2.78
Eastern region	Overall	12.91 ± 2.22	8.71 ± 1.12	11.41 ± 1.63	14.35 ± 2.67
	Elderly	2.29 ± 0.34	1.52 ± 0.18	1.86 ± 0.24	2.51 ± 0.54

PM: Particulate matter; URI: Upper respiratory infection.