Association between the First Occurrence of Allergic Rhinitis in Preschool Children and Air Pollution in Taiwan.

The occurrence of allergic rhinitis (AR) may be significantly influenced by air pollution. This study examined the association between the first occurrence of AR in preschool children and the pre-incident levels of air pollutants in Taiwan. We identified 9960 eligible subjects from a systematic sampling cohort database containing 400,000 insureds of the National Health Insurance from 2007 to 2011 and matched them with the environmental monitoring data from 2006 to 2011 according to the locations of their clinics. Pre-incident levels were determined using the average concentrations of air pollutants one or two weeks prior to the AR diagnoses. Logistic regression analyses were performed to determine any significant relationships between AR and specific air pollutants. The first AR incidence for Taiwanese preschool children, which increased with age, was 10.9% on average; boys appeared to have a higher percentage (14.2%) than girls (8.27%). Among the air pollutants, carbon monoxide (CO) and nitrogen oxides (NOX) were significantly related to AR after adjusting for age and gender (p < 0.05). Because both pollutants are considered to be traffic emissions, this study suggests that traffic emissions in Taiwan need to be controlled to lower the prevalence of children's AR.