Where are you riding? I finally left NorCal because I didn't want my child's lungs damaged by our toxic air. Bear in mind that some of the most polluted air in any region is on the roadways.

American Lung Association State of the Air report card grades for various NorCal counties:
Alameda-F
Contra Costa-F
Yolo-F
Amador-F
Calaveras-F
El Dorado-F
Nevada-F
Placer-F
Sacramento-F
Napa-C
Santa Clara-F
San Mateo-B
Tehama-F
Marin-A
Sonoma-A
Santa Cruz-A