Copd studies on effect of air quality on chronic bronchitis and asthma.

I live in Palm Desert and Long Beach, CA. I have been on meds for both chronic bronchitis and asthma for six months. Also allergy medicine.

In despair I went to Mammoth Mt for a week to see if I could still ski. By day three I felt better than I have in 18 months. No cough, no allergy meds, no sleepless nights. No problem with the elevation. No problem with reasonable exercise. Still taking all my other meds. It was snowing on and off so humidity was high, otherwise very dry. The most important variable is air quality, I believe.

What research has been on this variable?

Thanks for your help!

Colt Stewart