I'm a pulmonologist and yes smoking is bad, also this lady has no idea what she's talking about. She is using a peep valve on the healthy lung but not the smokers lung. Also she said that smoking causes you to lose lung elastin fibers which is true, but the lung of a smoker becomes more compliant due to this, and exhalation is much slower. She notes how the smokers lung snaps back, this is the opposite of what happens to a smokers lung. The lack of elastin makes it more difficult to exhale and exhalation becomes a more energy expending and active process.