Air pollution, fetal and infant tobacco smoke exposure, and wheezing in preschool children: a population-based prospective birth cohort

Table 3 Exposure to air pollutants in the previous month and wheezing in the same month

	Odds ratio of wheezing in previous month age 1 year (95% Confidence Interval)
	PM₁₀	NO₂
	n = 373	n = 373
Quartile 1	Reference	Reference
	n = 83	n = 72
Quartile 2	1.24 (0.90, 1.71)	1.28 (0.91, 1.79)
	n = 97	n = 87
Quartile 3	1.08 (0.77, 1.49)	1.54 (1.11, 2.13)*
	n = 82	n = 103
Quartile 4	1.38 (1.01, 1.88)*	1.62 (1.17, 2.24)**
	n = 111	n = 111
Trend	1.25 (0.98, 1.58)	1.32 (1.11, 1.55)
	p = 0.07	p < 0.01

Values are odds ratios (95% confidence interval) for wheezing from logistic regression models. *P < 0.05 and **p < 0.01. Models are adjusted for maternal age, education, parity, smoking, smoking of the partner, history of asthma or atopy and children’s sex, gestational age, birth weight, ethnicity, breastfeeding, daycare attendance, pet keeping and lower respiratory tract infections at age 1 year. Trend represents the risk of wheezing per 10 μg/m³ increase in PM₁₀ or NO₂.

ISSN: 1476-069X