New Ozone Standards

Smog Season officially began May 1. In March, ozone standards became more stringent. Why? Science shows us that even lower levels of air pollution can harm our health than previously thought. Atlanta's Clean Air Campaign compiled this Q&A to answer questions about the changes and what it means to Intown residents.

What changed?
On March 12, 2008, EPA strengthened the air quality standards for ground-level ozone, a primary component of smog. These new standards mean that lower levels of ozone will now be reported as unhealthy in the daily smog forecasts and in the Air Quality Index (AQI). The new "Code Orange" (101 - 150) level of the ozone AQI reflects ozone at 0.075 parts per million (ppm) or higher. The old standard was 0.084 ppm over an 8-hour average.

This more stringent standard is likely to result in more Smog Alert days than in previous years.The new scale is already incorporated into the AQI and does not change the fact that Smog Alerts are issued when a day is forecast to be Code Orange, Code Red or Code Purple.

Why was the change made?
There is increasing scientific evidence that shows that even low levels of exposure to ground-level ozone can be harmful. After a review of more than 1,700 new scientific studies, the EPA determined that new standards will yield health benefits of between $2 billion and $19 billion.The benefits include preventing cases of bronchitis, aggravated asthma and hospital and emergency room visits.

Breathing air containing ground-level ozone reduces lung function and increases respiratory symptoms for all, even the most healthy people.Ozone exposure may even contribute to premature death, especially with people suffering from heart and lung disease. Repeated exposure to ozone also damages sensitive vegetation and trees, leading to reduced growth and increased sensitivity to disease and pests.

Who should care the most?
Under the revised AQI, ozone levels above 0.075 ppm would be considered in the “Code Orange,” or “Unhealthy for Sensitive Groups” category. “Sensitive groups” are defined as active children and adults who are outdoors and likely to inhale ozone and people with respiratory ailments such as asthma.Some people suffer consequences even on Moderate air quality days.

How can I protect myself and my family?
The best way to protect yourself from the harmful effects of air pollution is to be informed. Sign up to receive Smog Alerts. Also, because more than half of all smog-forming pollutants in metro Atlanta come from cars and trucks, you can also help to reduce pollution by using a commute alternative.

What are Smog Alerts?
Each day, a team of scientists from the state Environmental Protection Division and Georgia Tech use a variety of meteorological and traffic pattern information to develop a forecast of the next day’s air quality. This forecast is made by 2 P.M. to provide you with timely information on which to base the next day’s activities, and to encourage actions to reduce pollution on those days when the air is expected to exceed federal standards.

Daily Smog Alerts are based on the Air Quality Index (AQI), which reflect the new standards. The color-coded tool is designed to provide easy to understand information about daily air pollution levels in their communities and the public health threat of poor air quality.

Facts About Ground-Level Ozone

Ozone is not emitted directly into the air, but is the result of a chemical reaction when chemicals are “cooked” by sunlight and heat. Nitrogen oxides react with volatile organic compounds to create ozone. The pollutants that form ozone waft into the air from motor vehicle exhaust, emissions from industry and power plants and vapors from gasoline and chemical solvents.

Ozone levels peak between 2 PM and 7 PM each day. Ground-level ozone is not to be confused with ozone found in the atmosphere’s upper levels.High in the atmosphere, ozone provides a benefit, protecting the earth from the sun’s harmful rays.