The mortality burden of airborne fine mineral dust in the United States

Carlos F. Gould , Wenxin Lu, Sam Heft-Neal, Mathew Kiang, Alexandra K Heaney

Regulation under the Clean Air Act has reduced combustion-derived fine particulate matter (PM2.5) in the United States, leaving windblown mineral dust—driven by drought, shrinking water bodies, and fallowed farmland—as a growing and largely unregulated share of what remains. Existing mortality burden estimates have had to borrow concentration–response functions from total PM2.5 and disagree fivefold. We link satellite-derived, source-speciated dust PM2.5 to a county-month panel of all cause mortality across 3,038 counties from 2000–2019, identifying effects from within county, within-season dust anomalies. Monthly mortality increases by 0.50% (95% CI 0.25–0.75%) per 1 μg/m3 dust PM2.5, controlling for co-occurring non-dust PM2.5, robust to the meteorology that generates dust, and is where background air is cleanest. We attribute roughly 8,000 deaths per year to ambient dust, rising to 11,000 when the response is accumulated over three months: $80–110 billion in annual mortality damages, one-third to one-half of recent estimates for wildfire smoke PM2.5 and one-tenth of total PM2.5 mortality in the US. Exposure falls disproportionately on Hispanic Americans and projected warming, drying, and current land and water management policies, are likely to increase dust’s impacts on health.