PM₂.₅ metals associated with pediatric respiratory visits in Shijiazhuang

Researchers examined short-term associations between airborne particulate metals and pediatric respiratory outpatient visits in Shijiazhuang, China, using daily data from 2020–2023. The observational study assessed concentrations of 12 PM₂.₅-bound metals and meteorological variables, applying generalized additive models for individual metals and quantile g-computation for mixtures. The supplied report did not specify the number of children or visits included.

Across lag days 0–7, each interquartile-range increase in lead concentration was associated with 13.188% more total visits (95% CI, 9.157%–17.369%); the corresponding estimate for zinc was 9.685% (95% CI, 5.612%–13.915%). Lead had the strongest association with acute upper respiratory infections, with an excess risk of 24.510%. Each decile increase in the eight-metal mixture was associated with a risk ratio of 1.041 (95% CI, 1.023–1.059), with lead and chromium receiving the highest mixture weights.

Zinc associations were stronger among children aged 7–14 years, with a statistically significant difference between age groups. Associations did not differ significantly between boys and girls. The findings support attention to metal components of air pollution but do not establish causality or individual-level risk. The single-city setting limits generalizability. Funding came from Shijiazhuang Scientific and Technological Projects, and the authors declared no competing interests.