Summary/Abstract
Extreme heat and wildfire smoke events are increasingly co-occurring in the context of climate change, especially in California. Extreme heat and wildfire smoke may have synergistic effects on population health that vary over space. Existing evaluations of climate-related health impacts generally estimates the influence of each climate hazard separately, and ignore potential synergistic effects between climate hazards.
In this peer-reviewed study, the authors used high-resolution satellite and monitoring data to quantify the way that compound exposures to extreme heat and wildfire smoke in California (2006–2019) varied between ZIP codes. The study found synergistic effects between extreme heat and wildfire smoke on daily cardiorespiratory hospitalizations at the state level. The authors also found spatial heterogeneity in such synergistic effects across ZIP codes. Communities with lower education attainment, lower health insurance coverage, lower income, lower proportion of automobile ownership, lower tree canopy coverage, higher population density, and higher proportions of racial/ethnic minorities experienced higher synergistic effects. This study highlights the need to incorporate compound hazards and environmental justice considerations into evidence-based policy development to protect populations from increasingly prevalent compound hazards.