Differential effects of size-specific particulate matter on lower respiratory infections in children: A multi-city time-series analysis in Sichuan, China

Evidence on the short-term effects of size-specific particulate matter with aerodynamic diameter ?2.5 ?m (PM2.5), ?10 (PM10), and their difference (PMC) children’s Lower Respiratory Infections (LRI) is scare. This study aimed to estimate differential three PM hospitalizations children aged <18 years for pneumonia bronchitis in 18 cities southwestern China. The city-specific association was firstly estimated using over-dispersed generalized additive model then combined obtain regional average association. Further, evaluate robustness key findings, subgroup analyses co-pollutant models were constructed. PM-related risks LRI differed by fractions cause-specific LRI. A 10 ?g/m3 increment PM2.5_lag03, PM10_lag06, PMC_lag06 associated a 0.79% (95% CI: 0.29%, 1.29%), 0.77% 0.13%, 1.41%), 2.33% 1.23%, 3.44%) increase hospitalizations, respectively. After adjustment gaseous pollutants, adverse types stable, ranging from 0.29% 0.05%, 0.54%) PM2.5–2.50% 1.38%, 3.64%) PMC. Additionally, PMC-related risk remained stable after pollutants. Associations PMC PM10 infants, PM2.5 6–17 years, PM2.5, PMC, 1–5 all statistical significant. Specifically, increased age, highest effect 1.72% (95%CI: 1.01%, 2.43%) years. Our provided evidence different Southwestern China, which will be useful making promoting policies air quality standards order protect health.