Wildfire Smoke PM₂.₅ and Daily Cause-Specific Mortality in 15 Colombian Cities, 2016–2023: A Multi-City Time-Series Study Using Distributed Lag Non-Linear Models

This study evaluated the association between daily wildfire smoke PM₂.₅ exposure and daily cause-specific mortality in 15 Colombian cities from 2016 to 2023. Daily mortality counts were obtained from DANE vital statistics. Wildfire smoke exposure was characterized using QFED, GFED, and FIRE_AVG. The analysis used Distributed Lag Non-Linear Models with quasi-Poisson regression, adjusting for temperature, relative humidity, long-term time trend, and day of week. The primary effect measure was the cumulative relative risk associated with a 10 µg/m³ increase in wildfire smoke PM₂.₅ over lag 0–30 days. Sensitivity analyses examined a shorter lag window, adjustment for the COVID-19 period, and exclusion of the COVID-19 period.