Ozone

Ozone in Metro Atlanta: Good News

As of August 2016, the Atlanta region is meeting the U.S. Environmental Protection Agency’s (EPA) 2008 ozone standard, making metro Atlanta a “maintenance” area rather than a “nonattainment” area.

The EPA has since introduced a tougher 2015 ozone standard. Areas will be designated for this standard in October 2017. While the exact boundary is uncertain, some portion of the region will likely be classified as a nonattainment area for the new standard.

In 2013, the Atlanta region was found to be in attainment with the 1997 ozone standard. As a result, the ozone nonattainment area boundary changed, removing Carroll, Spalding, Walton, Barrow and Hall counties. When designations for the 2008 standard became effective, the counties not part of the new boundary were removed from the requirements associated with ozone transportation conformity.

Chart - Ozone Levels in metro Atlanta
Ozone Levels in Metro Atlanta – Each line in the chart above represents readings over time from one of the nine ozone monitoring stations around the Atlanta region.

Facts about Ozone

Unlike other gaseous air pollutants, ground level ozone is not directly emitted by a source. Ozone is formed when volatile organic compounds (VOCs) and nitrogen oxides (NOx) react with extreme sunlight. Sources of VOCs and NOx include coal-fired power plants, gas stations, natural sources and gasoline-powered vehicles.

How ozone is created

Metro Atlanta has added more than one million people over the last decade, making ozone levels a persistent problem.

Effects on Health

In the short term, ozone can impact the respiratory system, causing irritation to the nose, throat and lungs. The long-term effects of ozone, inflammation in the lungs due to constant inhalation, can be compared to repeated sunburns and can lead to permanent scarring of lung tissue, loss of lung function and reduced lung elasticity.

Monitoring

U.S. EPA Ozone Classification SystemIn Georgia, the ozone monitoring season runs from March 1 to October 31, when temperatures are highest. However, ozone can be a problem year-round for sensitive populations. The Georgia Environmental Protection Division (EPD) maintains ozone monitoring data in Georgia.

The current standard for 8-hour ozone is 0.070 parts per million (ppm), which was set in 2015 by the EPA.

The federal Clean Air Act established a nonattainment area classification system for ozone based on the severity of the ozone problem. Areas with more severe designations are provided more time to demonstrate attainment, although the controls are more stringent.