Table 4.

Association between air pollution and childhood asthma in spring.

Pollutants		Modification Effect of Season in Spring
		Taipei			Kaohsiung
	Lag Day	OR	95% CI	p-Value	OR	95% CI	p-Value
PM2.5	0	0.944	0.744–1.198	0.640	0.930	0.589–1.470	0.758
	1	0.859	0.708–1.043	0.125	1.681	0.999–2.827	0.050
	2	0.998	0.823–1.210	0.987	1.394	0.854–2.275	0.183
	3	0.955	0.770–1.183	0.675	1.599	0.940–2.719	0.083
PM10	0	0.859	0.706–1.047	0.133	1.084	0.867–1.356	0.475
	1	0.953	0.850–1.068	0.412	1.289	0.897–1.854	0.169
	2	0.989	0.863–1.134	0.882	1.231	0.853–1.776	0.265
	3	0.864	0.712–1.048	0.139	1.310	0.948–1.808	0.100
O3	0	0.724	0.457–1.145	0.167	1.011	0.685–1.494	0.953
	1	1.576	0.968–2.565	0.067	1.374	0.896–2.105	0.144
	2	1.646 *	1.008–2.688	0.046	1.337	0.851–2.099	0.206
	3	1.908 **	1.178–3.091	0.008	1.168	0.753–1.810	0.486
SO2	0	0.996	0.743–1.336	0.983	0.958	0.526–1.743	0.889
	1	0.921	0.683–1.242	0.590	1.455	0.855–2.474	0.166
	2	0.964	0.720–1.291	0.808	1.292	0.708–2.354	0.402
	3	1.064	0.807–1.403	0.655	1.313	0.767–2.247	0.320
NO2	0	1.283	0.885–1.859	0.187	0.731	0.390–1.371	0.329
	1	1.009	0.693–1.468	0.961	1.205	0.597–2.429	0.601
	2	1.060	0.722–1.558	0.763	1.244	0.622–2.487	0.536
	3	0.896	0.583–1.375	0.615	1.094	0.541–2.212	0.802

Notes: * p < 0.05, ** p < 0.01.