Raphael’s field of teaching and research is primarily in air pollution, with the broad focus of his research on how features of the social and physical environment influence environmental exposures and health in resource-poor settings, particularly on vulnerable populations.

He has conducted in-country measurement on the spatial, socioeconomic, and temporal patterns of ambient, household, and personal air pollution in Accra, Ghana. Currently, he is working to address important questions in global health on how poverty, unsafe water and sanitation, lack of access to clean cooking fuel, and high levels of air pollution in cities disproportionately influence population health in low- and middle-income countries. For example, with collaborators from leading universities in Ghana, Canada, UK, Bangladesh, and China, coordinated by Imperial College London, Raphael is taking the lead on the Ghana component of a multi-investigator, multi-country project titled “Pathways to equitable healthy cities”, which aims to understand how actions related to water, sanitation, housing, transportation, and urban services affect health and health inequalities in cities. In another project, Raphael and his colleagues from the University of British Columbia and Oregon State University, are working on a global study assessing air pollution and cardiovascular and respiratory diseases in low- and middle-income economies within a large international cohort.