Early-life Household Environmental Exposures Increase the Risk of Childhood Asthma

Abstract

O-31C6-4 Background/Aims: The aim of this study is to explore the relationships between exposure to dampness, pets, and environmental tobacco smoke (ETS) early in life and asthma in Taiwanese children, and to discuss their links to early- and late-onset asthma. Methods: We conducted a 1:2 matched case-control study from the Taiwan Children Health Study, which was a nationwide study that recruited 12- to 14-year-old school children in 14 communities. The 579 mothers of the participants were interviewed by telephone about the environment their children were exposed to before they were 5 years old, and during their in-utero period. We used conditional logistic regressions for our statistical analysis. Results: Childhood asthma was associated with exposure to certain antagonists before the participants were 5 years old, such as cockroaches (odds ratio [OR] = 2.16; 95% confidence interval [CI]: 1.15–4.07), visible mould (OR = 1.75; 95% CI: 1.15–2.67), mildewy odors (OR = 5.04; 95% CI: 2.42–10.50), pets (OR = 2.11; 95% CI: 1.20–3.72), more than one cigarette daily (OR = 3.15; 95% CI: 1.93–5.15), and more than 1 hour of ETS per day (OR = 1.93; 95% CI: 1.16–3.23). Conclusion: Exposure to these factors led to dose-responsiveness in the risk of asthma. The ORs for mildewy odors, feather pillows, and ETS before the age of 5 years were greater among children with late-onset asthma. Cockroaches, pets, and ETS during pregnancy affected the timing of early-onset asthma. In-utero exposure to a greater number of smokers, duration, and amount of ETS led to higher risks of early-onset asthma for children (P < 0.05).