Ozone is a molecule of three oxygen atoms bound together (O3). It is unstable and highly reactive. "Good" ozone in the upper atmosphere protects us from harmful ultraviolet rays. However, the ozone that affects us negatively is ground-level air pollution that forms when emissions from cars, lawn & garden equipment or volatile substances (paints, solvents) bake in the sunshine. Ozone levels build up during the heat of the day under hot, sunny conditions with little to no wind.

"Nonattainment" is a U.S. EPA designation for any area that does not meet (or that contributes to ambient air quality in a nearby area that does not meet) the national primary or secondary ambient air quality standard for a National Ambient Air Quality Standard. As it pertains to ground level ozone, this means that concentrations of ozone often exceed federally accepted health risk based levels. There are further degrees of severity of nonattainment ranging from "Marginal" to "Extreme".  

Learn More about EPA's Ozone Nonattainment Classification System

The North Front Range Metropolitan Planning Organization is partnering with the Denver Regional Air Quality Council and the Colorado Department of Public Health and Environment to develop an ozone compliance plan, or SIP (State Implementation Plan).

• Stakeholder Involvement Process.

The reactivity of ozone causes health problems because it damages lung tissue, reduces lung function, and increases the sensitivity of the lungs to other irritants. Symptoms of decreased lung function include chest pain, coughing, sneezing and pulmonary congestion. Ozone can also act as an irritant to the mucous membranes of the eyes and throat and can reduce immune system capacity. In high concentrations, ozone causes damage to plants and deteriorates materials such as rubber and nylon.

Scientific evidence suggests that ozone affects not only individuals with respiratory problems, but also affects healthy adults and children.

Ozone action alerts are issued by the Colorado Department of Public Health during the summer ozone season (June 1 - August 31) based on daily forecasts of conditions that produce higher ozone levels. Ozone messages on any alert will be tailored to the expected ozone level so that groups at particular risk can be advised. Individuals can obtain a daily air quality advisory on-line. The State also operates a toll-free telephone hotline to help keep Colorado residents informed about current and predicted air quality conditions. The number is 1-888-484-3247 (1-888-4-THE AIR).

During ozone alert days, people can lower their risk of developing symptoms by limiting prolonged outdoor exposure. If ozone levels are moderately elevated, unusually sensitive individuals may experience symptoms and are encouraged to stay indoors as much as possible.

Ozone concentrations are also reported in the Fort Collins Air Quality Trends Reports.

For more recent ozone measurements in Fort Collins and other Colorado locations, see the Air Pollution Division web site.

During the summer season, and especially during ozone action alerts, everyone can do their part to reduce ozone pollution by taking voluntary and simple steps:

• Stop at the click when refueling
• Limit driving, combine trips or use alternative transportation
• Mow when the sun is low
• Use a spill-free gas can for fueling lawn and garden equipment