Abstract:
Objective To explore the influence of early-life exposure to air pollutants and greenness on asthma, rhinitis and eczema among preschool children.
Methods From November to December 2019, preschool children from 15 kindergartens in six urban districts of Taiyuan, China were surveyed for information on demographic characteristics, indoor environmental factors and incidence of atopic diseases by questionnaires, which were written by their parents. Questions focused on symptoms (in the last 12 months) associated with current wheezing, current rhinitis, and current eczema, as well as previous medical diagnoses including doctor-diagnosed asthma (J45.901), doctor-diagnosed rhinitis (J30.401), and doctor-diagnosed eczema (L23.901). At the same time, data on the mass concentrations of air pollutants (PM2.5, PM10, SO2, NO2, and O3) and the level of greenness (normalized difference vegetation index) in Taiyuan were obtained. Mixed effects logistic regression was applied to assess the effects of early-life air pollutants and greenness exposure on preschool children's atopic diseases.
Results A total of 4 814 preschool children aged 3~6 years were included. The mixed effects logistic regression analysis showed that prenatal exposure to O3-8 h significantly increased the incidence risk of children's doctor-diagnosed eczema (odds ratio, OR=1.007, 95% confidence interval, CI: 1.001~1.015). Infant O3-8 h exposure significantly decreased the incidence risks of current wheezing (OR=0.962, 95%CI: 0.934, 0.991), current rhinitis (OR=0.990, 95%CI: 0.978, 0.991), and doctor-diagnosed rhinitis (OR=0.962, 95%CI: 0.934, 0.999). Prenatal SO2 exposure significantly decreased the incidence risk of doctor-diagnosed eczema (OR=0.994, 95%CI: 0.990, 0.999). Infant SO2 exposure significantly reduced the incidence risk of current rhinitis (OR=0.993, 95%CI: 0.987, 0.999). Moreover, greenness exposure in infancy significantly reduced the incidence risk of current eczema in preschool children (OR=0.583, 95%CI: 0.342, 0.995).
Conclusion Early-life exposure to air pollutants and greenness was strongly associated with children's atopic diseases.