OZONE SEASON

The ozone season runs from April 1�October 31 each year�with ozone levels reported from May 1�September 30. Most of the Centralina Council of Governments region was included in the Environmental Protection Agency (EPA) designation of non-attainment for 8-hour ozone levels in April, 2004. As a result of this designation we need to be more aware of the actions taken by local government, business and industry and as individuals during this season. Centralina COG staff is available to assist you with developing a plan for your office or business. We can make a difference in the air quality of our region�are you willing to be a part of the solution?

If it's summertime, then it's Ozone time, too.



Ozone is a gas composed of three atoms of oxygen. Ozone occurs both in the Earth's upper atmosphere and at ground level. Ozone can be good or bad, depending on where it is found:

• Good Ozone. Ozone occurs naturally in the Earth's upper atmosphere -- 6 to 30 miles above the Earth's surface -- where it forms a protective layer that shields us from the sun's harmful ultraviolet rays. This beneficial ozone is gradually being destroyed by manmade chemicals. An area where the protective "ozone layer" has been significantly depleted-for example, over the North or South pole-is sometimes called "the ozone hole."
  
  
• Bad Ozone. In the Earth's lower atmosphere, near ground level, ozone is formed when pollutants emitted by cars, power plants, industrial boilers, refineries, chemical plants, and other sources react chemically in the presence of sunlight. Ozone at ground level is a harmful air pollutant.
  

QUESTIONS & ANSWERS ABOUT OZONE

Q: What exactly is ozone?
A: Ozone is a highly reactive gas that forms in the atmosphere when atoms of oxygen are combined through a chemical reaction. Ozone is not emit- ted directly into the air but, at ground level, is created by a chemical reaction between oxides of nitrogen (NOx) and volatile organic com- pounds (VOCs) in the presence of sunlight and heat.

Q: Isn�t ozone just an urban area problem?
A: Ozone levels generally are higher in urban areas, which contain more vehicles, industry and other emissions sources. However, winds can carry the threat of ground-level ozone from cities to surrounding rural areas and even to other states.

Q: Why do we need to do something about ozone?
A: High levels of ozone measured by monitors throughout ozone season have caused our non- attainment status. This is bad for business�it acts as an economic development deterrent and increases the cost for many businesses in the area to comply with air quality regulations. It also costs local governments money, in costs that they have to spend to meet additional transpor- tation conformity regulations. And if we don�t meet those regulations, it impacts our federal funding for both highway and transit transpor- tation projects. Finally, and in the long term most importantly, ozone is bad for our health and our children�s health.

Q: What are the health effects of ground-level ozone?
A: Ozone is unhealthy to breathe, particularly among sensitive groups: children, people with asthma and other respiratory ailments and anyone who works or exercises vigorously outdoors. Ground-level ozone can cause acute respiratory problems, aggravate asthma, significantly decreases lung capacity, cause inflammation of lung tissue and impair the immune system. Symptoms of ozone exposure can include coughing, throat, lung, and eye irritation, chest pain, rapid and shallow breathing and asthma attacks.

Q: Are there any non-health related problems associated with ozone?
A: High ozone levels can damage leaves on trees and crops, reducing growth rates and crop yields. Ground-level ozone damages plant life and is responsible for $500 million dollars in reduced crop production in the United States each year.

Q: What is an Ozone Action Day?
A: An Ozone Action Day occurs when ozone levels are forecasted to be a Code Orange, Red or Purple. On these days, ozone concentrations are predicted to exceed the proposed federal standard of 0.08 parts per million averaged over an 8-hour period. When the NCDAQ expects ground-level ozone concentrations to reach or exceed the standard in one of the forecast areas, a forecast for an Ozone Action Day is issued, indicating the expected color code as well as the numerical AQI value.