How does ground-level ozone affect public health?
When ground-level ozone (smog) levels are high, the respiratory system becomes irritated causing symptoms such as coughing, scratchy throat and tightness in the chest. As a result, lung function is reduced, the intake of air becomes strained and breathing can become uncomfortable.

In fact, roughly one of out of every three people in the United States is at a higher than average risk of experiencing ozone-related health effects. Smog can damage a person's lungs, trigger and intensify asthma attacks and aggravate other breathing conditions. There is also evidence that ground-level ozone can lower resistance to respiratory illnesses and chronic lung diseases, such as pneumonia, emphysema, asthma and bronchitis.

Some people have an unusual susceptibility to ground-level ozone. Scientists don't yet know why, but some otherwise healthy people may experience health effects at more moderate levels of exertion or at lower levels of smog pollution than the average person.

Who is more at-risk?
Active children are especially at risk because they often spend large parts of their summer playing outdoors. Asthma occurs more frequently in children and can be aggravated by prolonged exposure to ground-level ozone. Active people of all ages who exercise or work vigorously outdoors are more at risk to ground-level ozone than less active people.

Elderly adults and individuals with asthma or other respiratory diseases are more vulnerable to ground-level ozone because their lungs are weakened and generally experience health effects earlier and at lower levels than less sensitive individuals.

What is the Air Quality Index?
The Air Quality Index, or AQI, is a tool used for reporting daily air quality and the associated health effects. Levels of five major pollutants – ground-level ozone (smog), fine particles (soot), carbon monoxide, sulfur dioxide and nitrogen dioxide – are monitored and are used to provide the overall AQI score.

This score offers a glimpse of the quality of the air we breathe and what health effects may be noticeable. An AQI of 100 usually represents the national air quality standard that the EPA has set to protect public health. As a general rule, the higher the AQI value, the more air pollution and health risks there are.

For more information about the AQI, please visit the EPA's AIRNow website by clicking here.

Will health advisories be issued?
In Marion County, Knozone partners with the Marion County Health Department to issue a health advisory when ground-level ozone concentrations become unhealthy for the general population. This generally occurs when the Air Quality Index (AQI) reaches the red level, or unhealthy for all groups, due to very high pollutant readings. Ground-level ozone health advisories rarely occur in central Indiana.

• Ask employees to monitor their health during high ground-level ozone days. If they cough regularly, experience shortness of breath or have other breathing difficulties, suggest that they consult their physician.
• Limit or discontinue pollution-casuing operations that are non-essential on days when air pollution levels are high.
• Stay away from busy roads and other sources of air pollution when possible.
• Use indoor air conditioning when possible.
• Check the Air Quality Index (AQI) by called (317) 327-4AIR or by visiting the Knozone website. Communicate pollution levels to your employees throughout the day.