Table 5. Adjusted odds ratios (ORs) and 95% confidence intervals (CIs) for wheezing per 10-µg/m³ or 10-ppb increase in each pollutant during the study period.

	Single-pollutant model*				Two-pollutant model †
	OR ‡	95% CI		P value	OR ‡	95% CI		P value
	Wheezing in the morning
Indoor PM2.5(LD)
24-h mean	1.014	1.006	1.023	<0.001	1.015	1.006	1.024	<0.001
12-h mean	1.011	1.005	1.016	<0.001	1.011	1.005	1.017	<0.001
1-h maximum in the preceding 12 h	1.007	1.004	1.011	<0.001	1.007	1.004	1.011	<0.001
Outdoor PM2.5(LD)
24-h mean	0.993	0.980	1.006	0.271	0.997	0.983	1.010	0.624
12-h mean	1.001	0.988	1.014	0.888	1.002	0.990	1.015	0.707
1-h maximum in the preceding 12 h	1.003	0.994	1.011	0.559	1.003	0.993	1.012	0.591
Stationary-site PM2.5
24-h mean	1.014	0.987	1.042	0.301	1.020	0.978	1.063	0.363
12-h mean	1.013	1.000	1.026	0.052	1.020	0.995	1.046	0.119
1-h maximum in the preceding 12 h	1.014	0.997	1.031	0.119	1.015	0.993	1.038	0.184
Stationary-site NO2
24-h mean	0.995	0.971	1.019	0.670	-
12-h mean	0.998	0.979	1.016	0.808	-
1-h maximum in the preceding 12 h	1.002	0.991	1.014	0.675	-
	Wheezing in the evening
Indoor PM2.5(LD)
24-h mean	1.025	1.013	1.038	<0.001	1.025	1.012	1.038	<0.001
12-h mean	1.040	1.020	1.060	<0.001	1.040	1.020	1.062	<0.001
1-h maximum in the preceding 12 h	1.016	1.008	1.024	<0.001	1.016	1.008	1.025	<0.001
Outdoor PM2.5(LD)
24-h mean	1.016	1.002	1.029	0.024	1.010	0.996	1.026	0.170
12-h mean	1.014	1.002	1.026	0.022	1.017	1.001	1.033	0.041
1-h maximum in the preceding 12 h	1.002	0.992	1.011	0.739	0.998	0.988	1.009	0.764
Stationary-site PM2.5
24-h mean	1.033	1.008	1.058	0.009	1.027	0.984	1.073	0.219
12-h mean	1.022	1.004	1.042	0.019	1.024	0.994	1.055	0.116
1-h maximum in the preceding 12 h	1.006	0.997	1.016	0.177	1.002	0.990	1.014	0.700
Stationary-site NO2
24-h mean	1.024	0.996	1.052	0.093	-
12-h mean	1.011	0.990	1.033	0.293	-
1-h maximum in the preceding 12 h	1.014	1.001	1.028	0.035	-

PM_2.5, particulate matter less than 2.5 µm in diameter; PM_2.5(LD), PM_2.5 measured using the dust monitor with a laser diode; NO₂, nitrogen dioxide.

* : The association between wheezing and each pollutant was analyzed and adjusted for sex, age, temperature, and relative humidity.

† : The association between wheezing and each pollutant was analyzed and adjusted for NO₂ concentration, sex, age, temperature, and relative humidity.

‡ : ORs for wheezing associated with a 10 µg/m³ or 10 ppb increase of each pollutant.