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News Releases from Region 05

EPA and Ohio Propose Columbus Area Now Meets Federal Air Quality Standard for Ozone

Contact Information: 
Joshua Singer (

Columbus, Ohio – Today, the U.S. Environmental Protection Agency (EPA) and Ohio EPA announced their proposal to formally redesignate the Columbus area to attainment of the National Ambient Air Quality Standard (NAAQS) for ground-level ozone. Recent air monitoring data show the Columbus area now meets the national standard set to protect public health. 

“The air in the Columbus area is cleaner as a result of the cooperation between the state and federal governments,” said EPA Region 5 Administrator Cathy Stepp. “Columbus is a great example of the successful partnership between states, industry and the EPA to protect human health and the environment, and also spur economic development. In Region 5, working with our state partners, we are making such significant improvements in air quality that in the past two years Columbus would be the ninth area we’ve redesignated.”

“U.S. EPA’s recognition that the air quality in the Columbus metropolitan area meets the current national health-based standard for ozone reflects continuing progress in efforts to improve air quality and the quality of life for Ohio residents,” said Ohio EPA Director Laurie A. Stevenson.

The Columbus area was designated in 2018 as a marginal nonattainment area for the 2015 ozone NAAQS based on a multifactor analysis, including air-quality monitoring data. Several federal regulations pertaining to fuel standards and motor vehicle emission standards decreased emissions to help achieve the standard in the Columbus area.

Recent monitoring data show the Columbus area is currently attaining the 2015 National Ambient Air Quality Standard for ozone. EPA is proposing to redesignate the Columbus area to attainment and to approve Ohio’s plan to ensure that the area will continue to meet the ozone standard. Once an area has been redesignated, businesses seeking air permits face fewer permitting restrictions. The Columbus area’s redesignation will not be final until the public has an opportunity to comment on the proposal. If the redesignation is finalized, the Columbus area will be in attainment for all NAAQS. 

Nationally, the concentration of ground level ozone has decreased 17% from 2000 to 2017.

Ground level ozone is not emitted directly into the air but is formed when nitrogen oxides (NOx) and volatile organic compounds (VOCs) react in the presence of sunlight. Emissions from industrial facilities and electric utilities, motor vehicle exhaust, gasoline vapors, and chemical solvents are some of the major sources of NOx and VOCs. Breathing ozone can trigger a variety of health problems including chest pain, coughing, throat irritation and congestion. It can worsen bronchitis, emphysema and asthma. Ground level ozone also can reduce lung function and inflame the linings of the lungs. Children are at increased risk from exposure to ozone because their lungs are still developing. 

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