Long-term exposure to wildfire smoke and mortality: Heterogeneous effects by exposure metric and across subpopulations

As wildfires become more frequent and severe, the harmful effects of wildfire smoke are reaching beyond immediate impacts. Effects on mortality risk are persisting years after the initial exposure, leading to long-term consequences on affected populations. We found long-term exposure to wildfire smoke to be associated with higher mortality risk across various metrics of smoke exposure, with 3-y mean wildfire-related PM2.5 concentration showing the strongest effect. Individuals under age 75 and who identified as Black or in the Other race and ethnic group were most at risk. Wildfire-smoke related deaths are preventable, making it crucial to focus on actions that protect the most vulnerable and limit public health harms.