The EPA has just issued an “Orange” air quality warning for Chicago for Tuesday, July 28. The air quality index for ozone is predicted to be in the 101-150 range, indicating the air quality conditions are Unhealthy for Sensitive Groups. Unhealthy here means certain groups may experience health effects from the air quality, but the general public is not likely to be affected. For ozone the impacted groups are : Individuals with lung disease, children, older adults, and people who are active.
People with lung diseases, such as asthma, chronic bronchitis, and emphysema, can be particularly sensitive to ozone, and will experience more serious health effects at lower levels. Ozone pollution can leading to increased medication use, doctor and emergency room visits, and hospital admissions. Children are at higher risk from ozone exposure because their lungs are still developing, they are more likely to have asthma, and often play outdoors in summer when ozone levels are elevated. Older adults may be more affected by ozone levels, particularly if they have pre-existing lung disease. Active people of all ages who exercise or work vigorously outdoors are at increased risk due to prolonged exposure. Finally, some healthy people are more sensitive to ozone, without being in a sensitive group, suggesting a genetic basis for this increased sensitivity.
There are two important factors to consider to avoid being exposed to unhealthy air during times of increased pollution. First, minimize Prolonged Exertion — any outdoor activity that you’ll be doing off-and-on for several hours and that makes you breathe slightly harder than normal. Second, minimize Heavy Exertion — intense outdoor activities that cause you to breathe hard. It is very important to reduce your activity level if you experience any unusual coughing, chest discomfort, wheezing, breathing difficulty, or unusual fatigue.
The Air Quality Index (AQI) is an index for reporting daily air quality, indicating how clean or how unhealthy the air is. It is based on four major pollutants: ground level ozone, particle pollution, carbon monoxide, and sulfur dioxide. The AQI runs from zero to 500, with a value of 100 representing the national air quality standard for each of the pollutants. Values of 100 or below are considered satisfactory; at values over 100, the air is considered to be increasingly unhealthy.
The EPA AIRNow web site provides national air quality information, with links to detailed state and local air quality sites. You can access the Chicago Air Quality information here, and Illinois information here.