18 Mar (CLIM) Aboagye-Okyere, African Aerosols

Adwoa Aboagye-Okyere, Cornell U

Natural Aerosols as Drivers of Air Quality and Health in Africa

Wed, 18 Mar, 1:30pm via Zoom (for link, email bklinger@gmu.edu)

Host: Daniel Adjei

Aerosol pollution poses serious threats to human health and ecosystems, and natural aerosols such as dust and emissions from wildfires are likely to have changed substantially due to anthropogenic activities. Using the Community Earth System Model version 2, we simulated dust- and open-fire PM2.5 concentrations over Africa for preindustrial, present-day, and future scenarios. Health impacts were assessed using the integrated exposure-response model applied to gridded population and disease-specific mortality data. In the present day, we estimate that desert dust and open fires cause approximately 30,000 and 20,000 annual excess deaths, respectively, in Africa. Dust dominates PM2.5 concentrations at the continental scale, but lower population densities in dust-dominated regions limit its health impacts relative to combustion sources. Since preindustrial times, excess deaths due to dust and open fires have increased substantially. Across past, present, and future climates, natural aerosols account for more than 50% of PM2.5-attributable mortality in Africa, highlighting their importance for air-quality management.