The Louisville Air Pollution Control District has issued an air quality alert for Friday and Saturday. Ozone levels are forecasted to be high, and unhealthy for sensitive groups including the elderly, the young, and anyone with heart or lung ailments.These are the sixth and seventh alerts issued this year. The alerts are predictions, and so far, the air has not exceeded health standards on any alert days. However, yesterdaythere was no alert, and ozone levels did reach an unhealthy level for sensitive groups. It was the first time that happened this year.