Urban air pollution characteristics and associations with pre-school children respiratory health in four cities of Central China

The focus of this study was on the associations between air pollution, outdoor activities and symptoms of wheeze and rhinitis for pre-school children over Wuhan and surrounding cities. Air pollutants had downward trends over the study region from 2015 to 2020. Sulfur dioxide (SO2) content decreased significantly. Particulate matter was concentrated on the north side of the study area and nitrogen dioxide (NO2) was concentrated near Wuhan urban, while the distribution of ozone (O3) was relatively uniform. Odds Ratio (OR) showed that an increase in NO2 was associated with a high incidence of rhinitis, with an OR of 1.043 (1.025, 1.062 95% confidence interval). Reduction of O3 was associated with remissions of rhinitis symptoms in spring and autumn. The living environment is an important factor. Living near lakes was associated with the incidence of wheeze and living near roads was associated with the incidence of wheeze rhinitis, respectively. Additionally, appropriate outdoor activities showed association with a low incidence of wheeze and rhinitis symptoms in this region. This research improved our understanding of air pollution, outdoor activities and pre-school children's respiratory health. It was also a guide on the design of outdoor activities and outdoor courses for pre-school children during the process of urban construction.