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 Trends

PM2.5 Data Omitted from Air Trends Assessment

Through a combination of regularly scheduled technical systems audits of non-EPA laboratories processing state PM2.5 monitoring data and additional assessments of data quality, EPA has identified data quality issues that affect Florida, Illinois, most of Tennessee and parts of Kentucky. EPA has made a preliminary determination that this data should not be used for regulatory purposes. Until a final determination has been made, EPA has moved the data in the Air Quality System database for the PM2.5 sites in question from parameter code 88101 (PM2.5 at local conditions; used for regulatory data) to parameter code 88501 (PM2.5 raw data). This change will clarify to data users that data from these sites should not be compared to the PM2.5 National Ambient Air Quality Standards until EPA has made a final validity determination. This data is not included in the PM2.5 trends assessment or summary tables on this website.

Air Trends

  • Air Quality - National Summary
  • Air Quality - Cities and Counties
  • Air Quality Design Values
  • Previous Air Quality Trends Reports
  • Carbon Monoxide Trends
  • Lead Trends
  • Nitrogen Dioxide Trends
  • Ozone Trends
  • Particulate Matter (PM10) Trends
  • Particulate Matter (PM2.5) Trends
  • Sulfur Dioxide Trends
Contact Us About Air Trends
Contact Us to ask a question, provide feedback, or report a problem.
Last updated on March 26, 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.