Alexandra Heaney

and 5 more

Increasing wildfire activity across the Western US poses a significant public health threat. While there is evidence that wildfire smoke is detrimental for respiratory health, the impacts on cardiovascular health remain unclear. This study evaluates the association between fine particulate matter (PM2.5) from wildfire smoke and cardiorespiratory hospital visits in California during the 2004-2009 wildfire seasons. We estimate daily mean wildfire-specific PM2.5 with GEOS-Chem, a global three-dimensional model of atmospheric chemistry, with wildfire emissions from the Global Fire Emissions Database (GFED3). We defined a “smoke event day” as cumulative 0-1-day lag wildfire-specific PM2.5>= 98th percentile of cumulative 0-1 lag day wildfire PM2.5. Associations between exposure and outcomes are estimated using negative binomial regression. Results indicate that smoke event days are associated with a 3.3% (95% CI: [0.4%,6.3%]) increase in visits for all respiratory diseases and a 10.3% (95% CI: [2.3%,19.0%]) increase for asthma specifically. Stratifying by age, we found the largest effect for asthma among children ages 0-5y. We observed no significant association between exposure and overall cardiovascular disease, but stratified analyses revealed increases in visits for all cardiovascular, ischemic heart disease, and heart failure among non-Hispanic white individuals and those older than 65y. Further, we found significant interaction between smoke event days and daily temperature for all cardiovascular disease visits, suggesting that days with high wildfire PM2.5 and high temperatures may pose greater disease risk. These results suggest increases in adverse outcomes from wildfire smoke exposure and indicate the need for improved prevention and adaptations to protect vulnerable populations.