This paper introduces CPIE (Coal Pollution Impact Explorer), a spatiotemporal visual analytic tool developed for interactive visualization of coal pollution impacts. CPIE visualizes electricitygenerating units (EGUs) and their contributions to statewide Medicare deaths related to coal emissions. The tool is designed to make scientific findings on the impacts of coal pollution more accessible to the general public and to raise awareness of the associated health risks. We present three use cases for CPIE: 1) the overall spatial distribution of all 480 facilities in the United States, their statewide impact on excess deaths, and the overall decreasing trend in deaths associated with coal pollution from 1999 to 2020; 2) the influence of pollution transport, where most deaths associated with the facilities located within the same state and neighboring states but some deaths occur far away; and 3) the effectiveness of …