June 29, 2020
Estimation of pollution impacts on health is critical for guiding policy to improve health outcomes. Estimation is challenging, however, because economic activity can worsen pollution but also independently improve health outcomes, confounding pollution–health estimates. We leverage variation in exposure to local particulate matter of diameter <2.5 μm (PM2.5) across Sub-Saharan Africa driven by distant dust export from the Sahara, a source uncorrelated with local economic activity. Combining data on a million births with local-level estimates of aerosol particulate matter, we find that an increase of 10 μg m–3 in local annual mean PM2.5 concentrations causes a 24% increase in infant mortality across our sample (95% confidence interval: 10–35%), similar to estimates from wealthier countries. We show that future climate change driven changes in Saharan rainfall—a control on dust export—could generate large child health impacts, and that seemingly exotic proposals to pump and apply groundwater to Saharan locations to reduce dust emission could be cost competitive with leading child health interventions.