Claire Horwell is a Professor of Geohealth in the Department of Earth Sciences and Institute of Hazard, Risk & Resilience, Durham University, UK. Her research focuses on the health hazards and impacts of volcanic emissions and other air pollution events, and community protection. She is Director of the International Volcanic Health Hazard Network (www.ivhnn.org) which advises governments on health preparedness and response in volcanic eruptions, and provides evidence-based public information.