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Air Trends
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Nitrogen Dioxide Trends

Air quality monitors measure concentrations of NO2 throughout the country. EPA, state, tribal and local agencies use that data to ensure that NO2 in the air is at levels that protect public health and the environment. Nationally, average NO2 concentrations have decreased substantially over the years. The charts below show national and regional trends in NO2 concentrations. For information on NO2 standards, sources, health effects, and programs to reduce NO2, please see our Nitrogen Dioxide Pollution page.

National Trends

Starting in  1980 | 1990 | 2000 | 2010

 

Regional Trends

Region: Central | Northeast | South | Southeast | Southwest | West | Northern Rockies and Plains

 
How to interpret the graphs
How these regions are defined
  • Air Trends Home
  • 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 to ask a question, provide feedback, or report a problem.
Last updated on June 1, 2022
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