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Ground-Level Ozone and Health

Good and Bad Ozone: How Can It Be Both?

Ozone can be good or bad depending on where it is located. Most people know about the "good" or stratospheric ozone layer. It exists in the atmosphere nine to 31 miles above the earth and protects us from harmful ultraviolet rays. Stratospheric ozone also helps stop heat from escaping the earth. Without this "good" ozone, life as we know it would not exist. Closer to ground-level, up to two miles above the earth's surface, the formation of ozone is no longer helpful to us.

"Bad" ozone, also known as ground-level ozone or smog, causes air pollution and is harmful to our health and the environment. Stratospheric and ground-level ozone are identical in terms of their chemical make-up and this is what often causes confusion. What makes ozone "good" or "bad" is where it is located on the planet. And we can't just push up the ground-level ozone into the stratosphere.

How is "Bad" Ozone Formed?

Ground-level ozone is formed when fumes from sources such as cars, lawn and garden equipment, paints, power plants and factories are emitted into the air and react chemically in sunlight on hot summer days.

Nationally, 50% of these fumes come from motor vehicles. Industrial emissions from manufacturing and energy production facilities account for 20%. Emissions from area and off-road engine sources including boat engines, lawn mowers, beauty products, automobile refinishing and various cleansers, paints and solvents make up the remaining 30%.

On days when ozone levels reach particularly high levels, an Air Quality Advisory will be issued. On these days you are asked to take precautions and assist in keeping ozone levels down by limiting activities that contribute to the production of "bad" ozone.

How Are You and Your Family Affected?

The American Lung Association estimates cutting air pollution through the Clean Air Act will prevent at least 230,000 deaths and save $2 trillion annually by 2020. Children are more susceptible to the effects of ozone pollution. Due to their higher metabolic rates, children need more oxygen and therefore breathe more air - twice as much air per pound of body weight compared to adults (Journal of Environmental Health Perspectives).

Children spend significantly more time outdoors and are engaged in more vigorous activity resulting in breathing in more air, and therefore more pollution deep into their lungs.

The elderly, children, those with lung or heart ailments, and healthy adults who exercise outdoors on high ozone days are especially sensitive to ozone pollution. Ground-level ozone causes some significant health problems. It can irritate the respiratory tract, interfere with our ability to breathe freely, cause throat irritation, chest pain, coughing, inflammation of the lungs, and increase our susceptibility to lung infection. It also further aggravates roughly 573,000 residents in Wisconsin who have existing respiratory problems such as asthma, bronchitis, and emphysema.

Air pollution, including ozone, can result in more frequent respiratory infections in children due to the impairment of the lung’s ability to defend itself. Scientists are concerned that children who experience more frequent lower respiratory infections may be at greater risk of lower than normal lung function later in life.

We Wouldn't Settle For Dirty Drinking Water. So Why Should We Settle for Breathing Dirty Air?

Air Quality Advisories Information