Fine Particles in Wildfire Smoke and Pediatric Respiratory Health in California.

Abstract

Exposure to airborne fine particles with diameters ≤2.5 μm (PM_2.5) pollution is a well-established cause of respiratory diseases in children; whether wildfire-specific PM_2.5 causes more damage, however, remains uncertain. We examine the associations between wildfire-specific PM_2.5 and pediatric respiratory health during the period 2011-2017 in San Diego County, California, and compare these results with other sources of PM_2.5. Visits to emergency and urgent care facilities of Rady's Children Hospital network in San Diego County, California, by individuals (aged ≤19 years) with ≥1 of the following respiratory conditions: difficulty breathing, respiratory distress, wheezing, asthma, or cough were regressed on daily, community-level exposure to wildfire-specific PM_2.5 and PM_2.5 from ambient sources (eg, traffic emissions). A 10-unit increase in PM_2.5 (from nonsmoke sources) was estimated to increase the number of admissions by 3.7% (95% confidence interval: 1.2% to 6.1%). In contrast, the effect of PM_2.5 attributable to wildfire was estimated to be a 30.0% (95% confidence interval: 26.6% to 33.4%) increase in visits. Wildfire-specific PM_2.5 was found to be ∼10 times more harmful on children's respiratory health than PM_2.5 from other sources, particularly for children aged 0 to 5 years. Even relatively modest wildfires and associated PM_2.5 resolved on our record produced major health impacts, particularly for younger children, in comparison with ambient PM_2.5.