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. Air: Fate, Exposure, and Risk Analysis (FERA)

Consolidated Human Activity Database (CHAD) - Documentation for CHAD-Master

EPA maintains the Consolidated Human Activity Database (CHAD). CHAD contains data obtained from pre-existing human activity studies that were collected at city, state, and national levels. CHAD is intended to be an input file for exposure/intake dose modeling and/or statistical analysis. The documents below describe CHAD and its use.

  • CHAD Documentation and User’s Guide (pdf) (4.02 MB, October 2019, EPA-452/B-19-001)
  • Technical Memo, CHAD-APEX Updates - June 2019 (pdf) (883.78 KB)
    Further updates to CHAD

Air: Fate, Exposure, and Risk Analysis (FERA)

  • Total Risk Integrated Methodology (TRIM)
    • TRIM.FaTE
    • TRIM.Expo
    • TRIM.Risk
    • Peer Review and Publications
  • Multimedia Fate and Transport Modeling
    • TRIM.FaTE
    • Other Models and Related Information
  • Human Exposure Assessment and Modeling
    • Criteria Air Pollutant Exposure Assessment
    • Databases to Support Exposure Modeling
    • Air Pollutants Exposure Model (APEX/ TRIM.Expo Inhalation)
    • Hazardous Air Pollutant Exposure Model (HAPEM)
    • Other Models and Exposure-Related Information
  • Risk Assessment and Modeling
    • Air Toxics Risk Assessment
    • Criteria Air Pollutant Risk Assessment
    • Human Exposure Model (HEM)
    • EPA Risk Assessment Policy, Guidelines, and Related Materials
Contact Us about FERA
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on July 24, 2024
  • 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.