CO-Benefits Risk Assessment Health Impacts Screening and Mapping Tool (COBRA)
Description
EPA’s COBRA (Co-Benefits Risk Assessment) Health Impacts Screening and Mapping Tool estimates how changes in air emissions—especially from energy and climate policies—affect air pollution levels, health outcomes, and related economic benefits across U.S. counties. Users can input emissions changes or select built-in scenarios, and COBRA uses reduced-form air quality modeling plus health impact and valuation functions to produce quick, screening-level estimates of avoided deaths, illnesses, and monetized health benefits, along with maps and tables for communication and planning.
Questions this resource can help answer
If we reduce power plant or other sector emissions by a certain amount, how much PM2.5, premature mortality, and illness might we avoid by county or region?
Which policy option (e.g., different emission reduction levels, sectors, or target regions) yields the largest health and economic co?benefits?
How are the air quality and health benefits of a proposed climate or energy policy distributed across counties or states?
Do the estimated health benefits of an action plausibly exceed its implementation costs?
Which areas stand to gain the most health benefit per ton of emission reduction?
How do I use this resource?
To use EPA’s COBRA tool, download and install the software from EPA’s site. Enter or select changes in emissions (typically SO2, NOx, primary PM2.5, VOCs, NH3) by sector and county, or choose one of COBRA’s built?in policy scenarios. Then run the model: COBRA applies its internal air quality, health impact, and valuation modules to generate county-level results—changes in air pollution, avoided deaths and illnesses, and monetized health benefits—which you can view as tables, charts, and maps and export for reports or presentations.
Pro tips
Read the Instructions and FAQ once before editing inputs; most problems come from skipping these.
Start with a built?in scenario or a simple, single?sector change to learn the workflow before building complex scenarios.
Be clear about units and geography (e.g., tons/year by county) when entering emissions.
Use COBRA for screening and comparison (which option has larger health benefits), not for regulatory-grade estimates.
Keep a log of your assumptions and scenarios (which pollutants, sectors, years changed) so results are reproducible.
Pair COBRA outputs with local/contextual information before making policy recommendations.
Resource information
Technical specifications
COBRA uses a reduced-form air quality modeling approach coupled with standard health impact and economic valuation functions. User?specified emission changes (by pollutant and county) are fed into a source–receptor matrix that approximates how changes in precursor emissions alter ambient PM2.5 concentrations across U.S. counties. These concentration changes are then combined with baseline population and incidence rates using concentration–response relationships from epidemiological studies to estimate changes in health outcomes (e.g., premature deaths, hospital admissions, asthma attacks). Finally, COBRA monetizes these avoided impacts using values such as the value of a statistical life and cost per illness event.
