Thomas  Clasen

Rose Salamone Gangarosa Chair in Sanitation and Safe Water

Thomas Clasen, an epidemiologist, is the Rose Salamone Gangarosa Professor of Environmental Health at the Rollins School of Public Health, Emory University. After practicing international corporate law for twenty years, Prof. Clasen returned to school, obtaining a PhD in 2006.  Since then, he has led more than $45 million in research on household- and community-level environmental research in low-income countries and published more than 260 peer-reviewed papers in leading journals, including the New England Journal of Medicine, The Lancet, The BMJ, The Lancet Global Health, PLOS Med, Environmental Health Perspectives, WHO Bulletin, Epidemiology, and the International Journal of Epidemiology.  His research includes randomized controlled field trials to assess the health impact of water, and sanitation interventions, systematic reviews of water quality and sanitation interventions to prevent diarrhoeal disease and enteric infection, cost effectiveness analyses and project evaluations.  He leads the Household Air Pollution Intervention Network (HAPIN) trial, a multi-country trial to assess the health impact of LPG stove and fuel intervention in settings traditionally relying on solid biomass fuels. Additional current research includes the Revitalizing Informal Settlements and their Environments (RISE) study in Indonesia and Fiji testing the biological treatment of wastewater in urban slums, and the Climate Resilient Odisha Produce Study (CROPS) focusing on improving dietary diversity in remote, rural populations by using greywater in homestead gardens for heat- and flood-resilient produce.  Prof. Clasen was the chief scientific advisor to the World Health Organization in developing the first set of Guidelines for Sanitation and Health and is a member of the Technical Advisory Group for the WHO Secretariat on Health and Energy Plan of Action, and the WHO Scientific Advisory Group on Global Air Pollution and Health.  In 2025, Prof. Clasen was appointed Dean's Distinguished Scholar at the University of California--Berkeley School of Public Health.  Prof. Clasen holds an MSc (Control of Infectious Diseases) and PhD (Environmental Epidemiology) from the London School of Hygiene & Tropical Medicine where joined the faculty and achieved the rank of Professor of Water, Sanitation and Health.  He also holds a Juris Doctorate (Law) from Georgetown University and was a partner at Foley & Lardner, a US "BigLaw" firm.