Ozone is needed at high altitude, but the lazy, hazy days of Arkansas summers can lead to high levels of ground-level ozone where it can create health problems. Ozone Action Days is a program to inform residents about potentially harmful ground-level ozone, and gives advice how individuals can help reduce the problem.

Metroplan, the regional transportation-planning agency, manages Ozone Actions Days in partnership with the Arkansas Department of Environmental Quality, Arkansas Department of Health and the Arkansas Highway and Transportation Department.

Central Arkansas Regional Transportation Study director Casey Covington said ozone levels are of interest to Metroplan because federal transportation funds could be affected. "If the area falls into ‘non-attainment,’ it could mean increased federal regulation and scrutiny of how transportation funds are used," he said.

"Non-attainment" means an area has failed to meet clean air standards, Covington said.

Ozone is a naturally occurring gas in the upper atmosphere, at altitudes of about 6 to 30 miles, where it acts as a shield from the sun’s ultraviolet rays. However, ground-level ozone can cause a number of health problems including chest pain, coughing, throat irritation and congestion

Ground-level ozone develops when pollutants such as vehicle exhaust, fuel fumes, chemical solvents and industrial emissions are exposed to sunlight. Generally, elevated levels of ground-level ozone are most likely between the months of May through September.

Under the Clean Air Act, when an area is designated as in nonattainment, the state and state and local governments are required to take steps to reduce ozone levels to meet federal standards. The plan has to be detailed, technically supported and legally enforceable.

Reports from areas in the process of being designated in nonattainment show it has implications for economic development. Plans in some locales have included controls on industries using burners, boilers and heavy engines, as well as painting, coating and solvent users; new, stringent vehicle inspection and maintenance programs; reduced speed limits on highways and expressways; and more expensive gasoline.

For more immediate health concerns, AQI levels are indicated by a color code and warnings are issued any time the air quality reaches moderate levels:

•Green — Good — Air quality is satisfactory and poses little or no health risk.

•Yellow — Moderate — Air quality is acceptable, but pollution may pose a moderate health concern for a small number of individuals. People who are unusually sensitive to ozone or particle pollution may experience respiratory symptoms.

•Orange — Unhealthy for sensitive groups — members of sensitive groups may experience health effects, but the general public is unlikely to be affected.

•Red — Unhealthy — Everyone may begin to experience health effects; members of sensitive groups may experience more serious health effects.

•Purple — Very Unhealthy — Air quality that deteriorates to this triggers a health alert; everyone may experience more serious health effects.

•Maroon — Hazardous — This level triggers health warnings of emergency conditions; the entire population is even more likely to be affected by serious health effects.

Several groups of people are particularly sensitive to exposure to ozone, especially when active outdoors.

Children are at higher risk because they are outside more often, more likely to have asthma, which is aggravated by increased ozone, and their lungs are still developing.

Older persons with existing health problems may be more sensitive to elevated ozone levels. Lung diseases, such as asthma, chronic bronchitis and emphysema, can be aggravated by increased amounts of ozone. People with these conditions can expect to experience more serious health effects at elevated ozone levels. This can include needing increased medication, visits to the emergency room and doctor and hospital admissions.

Anyone who is performing prolonged or heavy exertion outside also is considered sensitive to elevated ozone levels.

Prolonged exertion is any intermittent outdoor activity done over several hours, such as yard work, that causes deeper breathing.

Heavy exertion is intense outdoor activity, such as running, biking or sports that cause a person to breathe deeply.

Reduce activity any time unusual coughing, chest discomfort, wheezing, breathing difficulty or unusual fatigue occurs.

For more information, go online to www.ozoneactiondays.org.

This article used information from the Environmental Protection Agency, Metroplan, and the city of Wichita (Kan.) report "Consequences of a Nonattainment Designator for Wichita MSA."