Ten Greenest Cities, Air Quality, 3:13pm, 03/12/2009

1. Portland, OR, 26, 35. 

2. San Francisco, CA, 21, 34. 

3. Boston, MA, 26, 25. 

4. Oakland, CA, 21, 34. 

5. Eugene, OR, 32.

6. Cambridge, MA, Good and Good. 

7. Berkeley, CA, Good and Good. 

8. Seattle, WA, 21, 31.

9.  Chicago, IL, 25, 45. 

10. Austin, TX, 19, 9.