Dr. Marirosa Molina is a Senior Research Microbiologist with the Office of Research and Development, Center for Environmental Measurement and Modeling. She recently relocated her lab to the Research Triangle Park in North Carolina from Athens, GA. Dr. Molina has a BS in Microbiology from the University of Puerto Rico-Mayagüez, a MS in Microbiology and a PhD in Ecology from the University of Georgia. Her research focuses on understanding the risk of exposure to microbial contaminants in ambient waters and their impact on human health. Dr. Molina’s research efforts have included development of tools that can assess microbial concentrations (pathogens and indicators of fecal contamination), stability and transport of microbial contaminants in ambient waters, application of microbial source tracking markers, and predicting the level of human health risk from various sources of contamination. Her efforts have provided the U.S. EPA with tools for the development of site-specific criteria for microbial contaminants where the level of risk can be specifically evaluated based on watershed characteristics, land use and climate changes.