These layers are a selection of the National Air Toxics Assessment (NATA) 2014 estimates of ambient concentrations and health-effect results by 2010 U.S. Census Tract. The Environmental Protection Agency (EPA) developed NATA as a screening tool to identify potential health risks from toxic air pollutants for further study. Please see NATA's website (https://www.epa.gov/national-air-toxics-assessment) for information about using NATA. This dataset is based on data from 2014 NATA, which was produced by the US EPA to estimate health risks from toxic air pollutants. It was modified for incorporation into the Compare my Area tool. The NATA results are available as downloadable data from https://www.epa.gov/national-air-toxics-assessment/2014-nata-assessment-results.