I live one city away from a big ozone factory! It just reeks every time I drive by it. No alerts though, dunno if we really need to be frightened about it, or not...
___The EPA has a great site in regards to Air Quality and its measurement. Makes for a good read at 03:00 AM when you don’t have anything else better to do … Like sleep! It will help you do that as well
The EPA’s and other government sponsored web site: AirNow