Carbon Monoxide
National Trends in CO Levels
Local Trends in CO Levels
National Trends in CO Levels
Using a nationwide network of monitoring sites, EPA has developed ambient air quality trends for carbon monoxide (CO). Trends from 1980-2007 and from 1990-2007 are shown here. Under the Clean Air Act, EPA sets and reviews national air quality standards for CO. Air quality monitors measure concentrations of CO throughout the country. EPA, state, tribal and local agencies use that data to ensure that CO remains at levels that protect public health and the environment. Nationally, average CO concentrations have decreased substantially over the years. For information on CO standards, sources, health effects, and programs to reduce CO, please see
www.epa.gov/air/urbanair/co.
Local Trends in CO Levels
Air quality trends can vary from one area to another. Local trends are available at individual monitoring locations with an adequate record of historical data.