U.S. Environmental Protection Agency (EPA) Region 5 said today that East Chicago and Indianapolis, Ind., now meet the health-based, outdoor-air standard for carbon monoxide.
EPA Regional Administrator Francis X. Lyons signed the authorization requiring the two areas to meet the health-based standard for carbon monoxide in early January.
Bharat Mathur, director of the regional Air and Radiation Division said, "By working closely with our state partners, we have reduced carbon monoxide to levels the protect public health and the environment."
Last year, EPA Region 5 redesigned two other highly-populated areas -- Detroit and Minneapolis-St. Paul -- to meet carbon monoxide standards.
To qualify for the redesignation, the areas had to meet a number of requirements, including taking steps to cut carbon monoxide pollution, monitoring data to support the clean-air designation, and setting up a plan to keep the air clean.
Measures taken by these areas to cut carbon monoxide levels include use of oxygenated fuel, cleaner cars, reduced traffic congestion and car engine idling, as well as air-pollution controls on some industries.
The national health-based, outdoor-air quality standard for carbon monoxide is 9 parts per million averaged over 8 hours.
Carbon monoxide is formed when carbon in fuel is not completely burned.
Cars and trucks produce approximately 60 percent of all emissions nationwide.
Peak levels usually occur during colder months when emissions are higher and when air pollutants are trapped near the ground under a layer of warm air.