Environmental health (EH) is the study of physical, chemical, and biological factors in the environment that affect human health. EH data include environmental exposures, health outcomes, and socioeconomic status (SES), which are often place-based or have geographic correlations. This chapter aims to develop students’ spatial literacy skills to address two EH themes—environmental disparities and exposure-health associations—with open online mapping tools. Environmental disparity studies address the disproportionate exposures among populations of low SES and of color. Students will learn to use EJScreen to display maps of emission clusters, pollution levels, and SES, and interpret their relationships. Environmental exposures are associated with multiple adverse health outcomes—e.g., respiratory and cardiovascular diseases. Students will explore the associations by comparing spatial patterns of exposure and disease generated with EJScreen and PLACES, respectively. Students will gain an impression of EH topics and online geospatial tools with class activities and examples.This activity is associated with a chapter in Spatial Literacy in Public Health: Faculty-Librarian Teaching Collaborations (ACRL, 2024).