Wildland Fires in the US between 2007 and 2018: Characterizing Equity in Exposures and Health Impacts

The burden of wildland fires to human health is well established, but less is known about how these impacts are distributed among vulnerable population groups and whether and to what extent wildland fire smoke affects certain parts of the country repeatedly. Moreover, much of the literature has focused on impacts from fine particles, but very few researchers have investigated deaths and illnesses attributable to ozone associated with wildland fires. This paper uses a 12-year time series of CMAQ model-predicted PM_2.5 and ozone concentrations between 2007 and 2018 and the BenMAP-CE tool to quantify the number, distribution, and economic value of these impacts. We calculate measures of inequality, including the Gini coefficient, to determine how these impacts are distributed among populations and locations. We estimate cumulatively tens of thousands of wildland fire PM_2.5- and ozone-attributable deaths, valued at $130B. Impacts occur disproportionately among those most vulnerable, as characterized by socioeconomic status in the Social Vulnerability Index, who experience a greater air pollution mortality burden as compared to those less vulnerable. A relatively small number of counties in northern California and Idaho experience a disproportionately high number of days of wildland fire PM_2.5 exposure. The Gini coefficient and Atkinson index indicate that counties with vulnerable populations are inequitably impacted, suggesting an opportunity for policies that could promote a more equitable burden of smoke to human health.