Air quality and children allergic diseases and neurodevelopmental disorders - A nationwide birth cohort follow-up approach

Abstract

Background and Aim Air pollution was associated with decreased lung function and intelligence. However, sizeable prospective follow-up studies with pre-and postnatal exposure considerations are scarce. The research is urgent due to the potential life-long lung and brain functional effects and the new WHO air quality guideline. In addition, extensive data-based investigations of two distinguished disorders might help examine potential confounders. The goal is to investigate prenatal exposure to nitrogen dioxide (NO2) and postnatal allergic diseases and neurodevelopmental disorders in a national-wide birth cohort. Methods We used the National Health Insurance Research Database (NHIRD) and the Taiwan Maternal and Child Health Database (TMCHD) to establish a national birth cohort born from 2007-to 2011 to follow the cumulative incidence of children's allergic diseases neurodevelopmental disorders till 2017. As a result, there were 759,142 infant-mother pairs finally included in the cohort without significant abnormalities. In addition, we utilized hybrid land-use regression models and machine learning methods to assess daily exposure to nitrogen dioxide (NO2) air pollutants, adopting the data of 76 national air-monitoring stations. Results The children experienced significantly increased allergic diseases [Hazard Ratio (HR), atopic dermatitis: 1.42 (Confidence Interval 1.38~1.45); asthma 1.21 (CI 1.19~1.23); allergic rhinitis: 1.22 (1.20~1.24)] and neurodevelopmental disorders [HR, autism: 1.52 (1.41~1.63); attention deficit hyperactivity disorder: 1.41 (1.36~1.46)] but not for epilepsy [HR, 1.04 (0.97~1.12)] with the 3rd tertile exposure to NO2 concentration (≥ 20.0 ppb) as compared to the lower (≤ 15.1 ppb) prenatally, adjusted for paid insurance amount, maternal smoking status, and parental history of the individual examined diseases in the Cox's model. Conclusion The incidence of children's allergic diseases and neurodevelopmental disorders increased significantly at the 3rd tertile of NO2 concentration before birth. Therefore, our result also corresponded to the new WHO guideline of optimized 20 ppb for NO2.