Skip to main content
U.S. flag

An official website of the United States government

Here’s how you know

Dot gov

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

HTTPS

Secure .gov websites use HTTPS
A lock (LockA locked padlock) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

    • Environmental Topics
    • Air
    • Bed Bugs
    • Cancer
    • Chemicals, Toxics, and Pesticide
    • Emergency Response
    • Environmental Information by Location
    • Health
    • Land, Waste, and Cleanup
    • Lead
    • Mold
    • Radon
    • Research
    • Science Topics
    • Water Topics
    • A-Z Topic Index
    • Laws & Regulations
    • By Business Sector
    • By Topic
    • Compliance
    • Enforcement
    • Laws and Executive Orders
    • Regulations
    • Report a Violation
    • Environmental Violations
    • Fraud, Waste or Abuse
    • About EPA
    • Our Mission and What We Do
    • Headquarters Offices
    • Regional Offices
    • Labs and Research Centers
    • Planning, Budget, and Results
    • Organization Chart
    • EPA History

Breadcrumb

  1. Home
  2. CO-Benefits Risk Assessment Health Impacts Screening and Mapping Tool COBRA

How Does COBRA Work?

COBRA contains detailed emission estimates of PM2.5, SO2, NOx, and VOCs for the year 2016, and detailed projections for 2023 and 2028 as developed by the U.S. EPA. Users create their own scenario by specifying increases or decreases to one of the three baseline emission estimates - 2016, 2023, or 2028. Emission changes can be entered at the county, state, or national levels, and outcomes can be modeled nationwide or for smaller geographic areas.

COBRA uses a reduced form air quality model, the Source-Receptor (S–R) Matrix, to estimate the effects of emission changes on ambient PM and ozone.

Using an approach to estimating avoided health impacts and monetized benefits that is generally consistent with EPA practice, the model translates the ambient PM and ozone changes into human health effects and monetizes them.

Users can view the results in tabular or geographic form.

  • How COBRA Works (pdf) (417.07 KB)

CO-Benefits Risk Assessment Health Impacts Screening and Mapping Tool COBRA

  • Download Desktop Edition
  • Use COBRA Web Edition
  • Frequently Asked Questions
  • Contact EPA About COBRA
Contact Us About COBRA
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on April 3, 2025
  • Assistance
  • Spanish
  • Arabic
  • Chinese (simplified)
  • Chinese (traditional)
  • French
  • Haitian Creole
  • Korean
  • Portuguese
  • Russian
  • Tagalog
  • Vietnamese
United States Environmental Protection Agency

Discover.

  • Accessibility Statement
  • Budget & Performance
  • Contracting
  • EPA www Web Snapshot
  • Grants
  • No FEAR Act Data
  • Plain Writing
  • Privacy
  • Privacy and Security Notice

Connect.

  • Data
  • Inspector General
  • Jobs
  • Newsroom
  • Regulations.gov
  • Subscribe
  • USA.gov
  • White House

Ask.

  • Contact EPA
  • EPA Disclaimers
  • Hotlines
  • FOIA Requests
  • Frequent Questions
  • Site Feedback

Follow.