Fenna C. M. Sillé, PhD, MS, is an Assistant Professor in the Department of Environmental Health and Engineering at the Johns Hopkins Bloomberg School of Public Health, where she also serves as Deputy Director of the Center for Alternatives to Animal Testing (CAAT) and the Director of the JHU Exposome Collaborative. Guided by the motto “a healthy environment = healthy people,” Dr. Sillé investigates how the exposome shapes immune function and disease across the life course. Focusing on early-life and chronic exposures—especially arsenic and heavy metal mixtures—her work examines systemic and immune-related impacts on vaccine responses, infection and cancer risk, and neuroinflammatory pathways tied to neurodevelopmental and neurodegenerative outcomes. She also leads a study characterizing the exposome in relation to childhood asthma in Baltimore City.

At CAAT, she directs the metabolomics lab and chairs the International Developmental Immunotoxicity (DIT) Working Group to accelerate the development, qualification and adoption of new approach methodologies (NAMs) for immune safety—part of her broader leadership in the CAAT Implementation Moonshot Project for Alternative Chemical Testing (IMPACT) aimed at modernizing chemical testing with human-relevant science. As the director of the JHU Exposome Collaborative, and the lead for the CAAT IMPACT Exposome Program, her efforts are aimed towards realizing The Human Exposome Project, by co-developing practical tools and infrastructures for the field, including the tidyexposomics R toolkit, and advancing “exposome intelligence”—integrating AI with exposomics to accelerate discovery and translation for precision public health and medicine.

Dr. Sillé recently led the organization of the Exposome Moonshot Forum, gathering diverse stakeholders (including governments, organizations, scientists, funders, the technology sector and the public) and fostering global dialogue and collaborations around exposome-informed health policy and practices. This led to the Washington, D.C. Declaration on the Human Exposome and the formation of the Global Exposome Forum (GEF), which she is co-leading. GEF is a growing international consortium dedicated to the realization of The Human Exposome Project. She also helped start the Global Exposome Summit series, to facilitate exchange and collaboration among the global exposome community.

Dr. Sillé earned an MS in immunology and molecular virology from the University of Groningen in 2004, and her PhD in Immunology in 2010, as a Boehringer Ingelheim Fonds Fellow for research performed at Harvard University and Brigham & Women’s Hospital, followed by postdoctoral work in functional genomics and environmental health at UC Berkeley (2011-2016).