Whatcom County gets an A from American Lung Association in thier latest American Lung Association State of the Air: 2007 report. Washington State as a whole did pretty well. We are so lucky to have good clean air here. I remember when I first moved to Mountain View, CA in 1970 and live there several months before I ever saw the mountains and then realized where the cities name came from.
You can check out your state and county at The American Lung Association web site