Bisphenol A Exposure and Asthma Development in School-Age Children: A Longitudinal Study

BACKGROUND: Although the effect of bisphenol A on various health outcomes has been extensively examined, few studies have investigated its effect on asthma. OBJECTIVE: We hypothesized that exposure to bisphenol A in school-age children was associated with wheezing and asthma. METHODS: Participants included 127 children aged 7–8 years without a previous asthma diagnosis in an elementary school in Seoul, Korea. Three surveys were conducted, each 2 years apart. Bisphenol A concentration was measured at the baseline survey, and PC(20), which is defined as the methacholine concentration that induces a decrease in FEV(1) of 20% from baseline, was measured at every survey. Associations between bisphenol A concentration at 7–8 years of age and wheezing, asthma, and PC(20) at ages up to 11–12 years were examined using generalized estimating equations, a marginal Cox regression model, and a linear mixed model. RESULTS: The log-transformed creatinine-adjusted urinary bisphenol A concentration at 7–8 years was positively associated with wheezing (odds ratio, 2.48; 95% confidence interval, 1.15–5.31; P = .02) and asthma (hazard ratio, 2.13; 95% confidence interval, 1.51–3.00; P<.001) at ages up to 11–12 years. Bisphenol A was also negatively associated with PC(20) (ß = −2.33; P = .02). When stratified by sex, the association between bisphenol A and asthma remained significant only in girls (hazard ratio, 2.45; 95% confidence interval, 2.18–2.76; P<.001). CONCLUSION: Increased urinary bisphenol A concentrations at 7–8 years old were positively associated with wheezing and asthma and negatively associated with PC(20) at ages up to 11–12 years.