The Proximity Tool (ProxTool) is used to characterize the size and demographic make-up of populations living within a user specified area around facilities or other locations of interest. User inputs to the tool include an ID for each facility (or location), the latitude and longitude for each facility (or location), and the radius of the circular area of interest surrounding each facility (or location) in kilometers (km) up to 50 km (e.g., 5 km radius). It should be noted that proximity to affected facilities does not indicate that any exposures or impacts will occur and should not be interpreted as a direct measure of exposure or impact.