An official website of the United States government.

This is not the current EPA website. To navigate to the current EPA website, please go to This website is historical material reflecting the EPA website as it existed on January 19, 2021. This website is no longer updated and links to external websites and some internal pages may not work. More information »

Energy Resources for State and Local Governments

User’s Manual for the Co - Benefits Risk Assessment (COBRA) Screening Model

Co-Benefits Risk Assessment (COBRA) Health Impacts Screening and Mapping Tool is a screening tool that provides preliminary estimates of the impact of air pollution emission changes on ambient particulate matter (PM) air pollution concentrations, translates this into health effect impacts, and then monetizes these impacts.

This User Manual will acquaint you with the the tool, provide a quick-start tutorial, and options for data, scenarios, and results.

You may need a PDF reader to view some of the files on this page. See EPA’s About PDF page to learn more.