Ozone hurts our health.
Studies link air pollution to harmful health effects - especially among people who are particularly sensitive to ozone like active children (at highest risk), older adults, active adults of all ages who work or exercise outdoors, people with asthma or other respiratory diseases and people with an unusual susceptibility to ozone.

While people who are active outdoors (breathing faster and more deeply) feel the effects of ozone earlier, as concentrations of ground-level ozone increase, more people experience health effects and more people are admitted to the hospital for respiratory problems. When ozone levels are very high, everyone should be concerned about ozone exposure.

Ozone hurts our economy.
If Dane County or surrounding areas exceed federal air pollution standards, we may be designated as a “non-attainment” area. This would mean imposing mandatory regulations to reduce air pollution that could cost Dane County citizens and businesses millions of dollars each year.

Ozone even hurts crops, forests and native plants.
Some susceptible species include black cherry, trembling aspen, milkweed, blackberry, tobacco, soybean and clover.

What is ozone?
GOOD OZONE: Ozone occurs naturally in the Earth's upper atmosphere - 10 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, often referred to as the ozone layer, is gradually being depleted by manmade chemicals.

BAD OZONE: In the Earth's lower atmosphere - our breathing space - high concentrations of ozone (along with harmful fine particles and toxins) are created from our pollution when it reacts chemically in sunlight, especially in summer months when temperatures are high.

Nearly one-half of Dane County's pollutants comes from our cars and trucks, as well as other gasoline and diesel engines that power everything from construction equipment to lawn mowers. Electric power plants burning fossil fuels and smaller businesses that use ozone-generating materials also contribute to the problem.

How is ozone measured?
The Department of Natural Resources has a statewide network of 33 ozone monitoring stations. Every hour, the ozone monitor calculates the average amount of ozone in the air. If the 8-hour average is below 0.08 parts per million (ppm), the local air quality meets the federal health standard for ozone. If the 8-hour average is at or above 0.08 ppm, the area has exceeded the health standard.