Alexandra Shtein is a postdoctoral fellow in the Department of Environmental Health at Harvard T. H. Chan School of Public Health. Her postdoctoral research deals with improving air pollution estimations over the contiguous US using satellite-based observations and machine learning models. Alexandra Shtein’s PhD, in the Geography and Environmental Development of Ben-Gurion University, focused on developing a statistical hybrid modeling approach that aims to provide spatiotemporally resolved estimates of particulate matter (PM) pollutants over Israel and Italy. The improved estimates from these models are used in epidemiological research to study the associations between air pollution exposure and adverse health outcomes.