Study on the impact of air pollutants on childhood asthma in Nanjing based on a distributed lag non-linear model

Asthma, a chronic respiratory disease, is a significant public health concern globally. Air pollution has been identified as one of the key risk factors exacerbating respiratory conditions, particularly in children. Previous studies have shown a correlation between air pollution levels and asthma visits. However, the impact of air pollutants on childhood asthma visits stratified by gender, age and season remains a topic of interest, and further investigation is necessary to comprehend this complex relationship.

This study aimed to explore the association between air pollution and childhood asthma visits in Nanjing from 2013 to 2021. It focused on the effects of various pollutants, including PM_2.5, PM₁₀, NO₂, SO₂, CO, and O₃, and examined variations in impact based on demographic characteristics (gender and age) and seasonal changes.

Data on childhood asthma visits and concentrations of air pollutants were collected and analyzed. The lag effects of pollutants on asthma visits were assessed, and the impacts were stratified by gender, age group (0-5 years, 6-11 years, and over 11 years), and season. Statistical methods were used to identify significant correlations and the timing of maximum effects of pollutants.

A positive correlation was found between childhood asthma visits and concentrations of AQI, PM_2.5, PM₁₀, SO₂, NO₂, and CO, with the strongest effects typically occurring on lag day 1. The study revealed that PM_2.5 and PM₁₀ had a more pronounced impact on females, and children aged 0-5 years were the most affected age group. Seasonal analysis showed that PM_2.5 and SO₂ had the greatest impact in spring, while PM₁₀ and NO₂ were most significant in winter. Notably, SO₂ showed no significant impact on childhood over 11 years old or during summer, and the negative correlation between CO concentrations and childhood asthma visits in the summer, while in other seasons, the correlation was positive.

The findings indicate a substantial effect of air pollutants, particularly PM_2.5 and SO₂, on childhood asthma, emphasizing the need for targeted pollution control measures. Variations in impact based on gender, age, and season suggest the importance of tailored interventions to protect vulnerable populations, especially young children in urban and industrial areas.