Claire J Horwell

Claire Judith Horwell is a Professor of Geohealth in the Department of Earth Sciences and Institute of Hazard, Risk and Resilience at Durham University and the founding Director of the International Volcanic Health Hazard Network (IVHHN). She studies the health hazards of natural and industrial mineral dusts.

Horwell became interested in volcanoes as a child when she visited Mount Batur in Bali at the age of seven. Her undergraduate degree was in Environmental Science at the University of East Anglia, UK, where she studied environmental, earth and public health sciences. She moved to Victoria University of Wellington for her master's degree, and studied volcanology. Her research at Victoria University was based in Rotorua, an urban area where 60,000 people are exposed to geothermal emissions. Horwell designed devices to measure gas emissions around the town, collecting information on hydrogen sulphide exposures and providing advice to public health experts. She earned her doctorate at the University of Bristol, where she worked with Robert Stephen John Sparks supported by the Natural Environment Research Council. Her PhD research focused on the characteristics of crystalline silica in volcanic ash which control its toxicity. In 2003, Horwell founded the International Volcanic Health Hazard Network (IVHHN), which provides information on the health hazards and impacts of volcanic emissions to the general public and civil protection agencies. She has remained as the director of the IVHHN, and has since co-created the Hawaii Interagency Vog dashboard to provide information about volcanic smog to the general public. In 2005, Horwell joined the University of Cambridge as a NERC postdoctoral fellow. She moved to Durham University in 2007 as a Research Councils UK research fellow where she is now Professor.

Horwell has served as an advisor to the World Health Organization, UK Cabinet Office and Public Health England. She was appointed to the Government of the United Kingdom Scientific Advisory Group for Emergencies for volcanic eruptions in 2015. She is currently President-elect and founding leader of the American Geophysical Union's GeoHealth Section and serves on AGU's Council.

Horwell studies the health hazards of mineral dusts, and ways to support communities to protect themselves from inhaling particulate air pollution. She uses physicochemical analysis to establish whether or not mineral particles are harmful, as well as toxicological assessments to determine the respiratory hazards. These help her to understand the structure-toxicity relationships of minerals. She has studied how crystalline silica forms in volcanic systems such as lava domes using petrological techniques, including X-ray diffraction. Crystalline silica can be a pathogen, and can result in silicosis and lung cancer. Horwell is trying to establish whether the silica in volcanic ash has the potential to cause these diseases. Horwell worked with authorities in Hawaii to help local communities respond to the Kīlauea vog (volcanic smog) emissions. The Interagency Vog Dashboard website was accessed over 50,000/week during the 2018 lower Puna eruption.

She has worked with the Pan American Health Organization to introduce new epidemiological protocols for use in volcanic crises and supports many governmental agencies and non-governmental organizations in Indonesia, New Zealand, Singapore, Japan and Mexico in preparing for community exposures to volcanic emissions. She created the Health Interventions in Volcanic Eruptions (HIVE) project to collect evidence on respiratory protection for communities. She investigated the effectiveness of facemasks distributed by agencies during volcanic eruptions, looking to identify whether or not they could adequately filter fine-grained particles, as well as to understand the behavioural reasons why some communities may or may not wear masks, through collaborations with a range of social scientists. During this program Horwell co-developed train-the-trainer courses with the International Society for Respiratory Protection to teach people in Indonesia how to better protect themselves. Her research, with the Institute of Occupational Medicine, confirmed that N95 industry certified masks are most effective at protecting communities from inhaling volcanic ash, and that the more commonly used surgical masks offered less protection.

Awards and honours

Her awards and honours include;

• 2020 European Geosciences Union Plinius medal for interdisciplinary natural hazards research
• 2020 American Geophysical Union GeoHealth Section President and Founding Leader

Selected publications

Her publications include;

• Horwell, Claire J.; Baxter, PJ. (2006-07-01). "The respiratory health hazards of volcanic ash: a review for volcanic risk mitigation". Bulletin of Volcanology. 69: 1–24. doi:10.1007/s00445-006-0052-y.
• Witham, Claire S.; Horwell, Claire J. (2005-03-15). "Volcanic ash-leachates: a review and recommendations for sampling methods". Journal of Volcanology and Geothermal Research. 141 (3–4): 299–326. doi:10.1016/j.jvolgeores.2004.11.010.
• Horwell, Claire J. (2007). "Grain-size analysis of volcanic ash for the rapid assessment of respiratory health hazard". Journal of Environmental Monitoring. 10: 1107–1115.