As I battle my latest round with bronchitis, a light goes on: My increasing bouts with respiratory problems increased sharply after we left polluted urban environments and moved to the clean air of the mountains.

Since moving here in 2004, both Amy and I have encountered allergies we never knew we had.

Maybe it’s the clean air. Maybe after so many years living in toxic environments, our lungs can’t take fresh air.

Sounds ridiculous. Or maybe not.

Amy was born in East St. Louis, Illinois — hardly a shining example of clean air and green living. The Metro East area of St. Louis was a lung-contaminating hodgepodge of oil refineries, steel factories and ammunition plants.

I moved to Metro East in 1969 and lived there for nearly 12 years, breathing the air from the refineries in Hartford, Illinois, and the coal-fired electric plant in Portage Des Sioux, Missouri just acorss the Mississippi River.

We moved to the Washington, DC, area in 1981 and lived there for 23 years, breathing the exhaust fumes of cars in one of the most traffic-clogged regions of the country. My profession took me to some of the most toxic places on earth, ranging from the polluted air of East Germany and the Far East to arsenic-filled leach pit ponds of gold mines in the Western United States.

Neither of us had much problems with allergies or respiratory problems then. For both, problems set in after we moved to the mountains where the air is clear and the water clean (well, except for the iron sulphate).

Maybe our lungs are in full rebellion, revolting against air they can’t see.

Or maybe we’re just finally paying the price for breathing too much polluted air in too many other places on earth.