“What can I do to keep my lungs healthy?”

Avoid cigarette or tobacco smoke, smog, fumes, dusts, chemicals in the air, and allergens, exercise, keep your weight down, do all you can to keep your heart healthy (treat high BP and keep your BP less than 130/80 or so), maintain a healthy cholesterol level (with an LDL less than 100 or so), exercise 30 minutes a day or so, keep weight down to avoid type 2 diabetes and undue stress on the heart and lungs, and live in a place with clean, dry air, and away from industry, factories, bad air emissions/smog (i.e., heavy traffic, etc.).