Time-Series Analysis of Atmospheric Pollution and Mycoplasma pneumoniae Infections in Children

Objective: Aimed to analyze the relationship between air pollution and Mycoplasma pneumoniae (MP) infection in children in Chengdu. Method: Data on outpatient and inpatient cases of MP infection among children at Chengdu Women and Children's Central Hospital from 2019 to 2023 were retrospectively collected. Air pollution and meteorological data from the same period were also obtained. A generalized additive model (GAM) was established using R statistical software to examine the impact of different air pollutant concentrations on MP infection incidence in children. The relationship between pollutant concentrations and MP infection rates was further analyzed by stratifying data by age, sex, and season. Results: From 2019 to 2023, a total of 21,075 outpatient and emergency cases and 6964 inpatient cases of MP infection were reported among children at Chengdu Women and Children's Central Hospital. A 10-μg/m³ increase in the daily concentration of particulate pollutants (PM_2.5, PM₁₀) had the most significant delayed effect on outpatient MP infection incidence at a 6-day lag (lag 06), although the cumulative lag effect was not statistically significant. When the average daily concentration of gaseous pollutants (SO₂) increased by 10 μg/m³, the strongest lag effects on outpatient and inpatient MP infections were observed at 7-day lags (lag 07 and lag 7, respectively). In the single air pollutant model, age-stratified analysis showed that SO₂ concentration had the most significant correlation with the incidence of outpatient and inpatient MP infections in children under 6 years of age, while nitrogen dioxide (NO₂) concentration had the most significant correlation in children over six. Sex-stratified analysis indicated that SO₂ levels were most significantly associated with MP infection in males, whereas NO₂ were most strongly correlated in females. Among outpatients, SO₂ had the most substantial effect on MP infection incidence across sexes. Seasonal stratification revealed that the impact of air pollution on MP infection was greater in autumn and winter than in spring and summer. Conclusion: Increased air pollution levels in Chengdu from 2019 to 2023 had a measurable impact on MP infection incidence in both inpatient and outpatient children, with notable lag and cumulative lag effects. These effects were more pronounced in autumn and winter, highlighting the need for targeted early warning systems to monitor air pollutant concentrations. Such efforts could play a crucial role in protecting vulnerable populations and reducing MP infection risks in children.