Exposure to Anthropogenic Heat Was Associated with the Increased Risks of Respiratory Allergy Symptoms in Preschool Children: A New Insight into the Urban Heat Island Effect.

Anthropogenic heat (AH) exerts a substantial influence on the local urban climate and intensifies the urban heat island (UHI) effect. However, the impact of AH exposure on respiratory allergy symptoms in preschool children has not been investigated. This study conducted a cross-sectional study of 39088 Chinese preschool children to investigate the associations between multisource AH exposure (building heat, industrial heat, metabolic heat, transportation heat, and total heat) and the risks of respiratory allergy symptoms (wheezing, night-cough, and rhinitis). Exposure to higher levels of AH was associated with increased risks of wheezing (building heat, transportation heat, and total heat), night-cough (building heat), and rhinitis (building heat, metabolic heat, transportation heat, and total heat) symptoms. Exposure-response relationships demonstrated positive relationships between AH with wheezing, night-cough, and rhinitis symptoms, with nearly linear and inverted "J" shapes. Building heat contributed most to the impact of multisource AH on wheezing, night-cough, and rhinitis symptoms, with weighted quantile sum weights ranging from 0.513 to 0.887. Our study provided new epidemiological insights into the impact of the UHI effect on childhood respiratory allergies and highlighted that mitigating AH exposure, specifically from building heat, could be an effective strategy for reducing the disease burden of respiratory allergies in children.