Just the opposite here and no problems after tobacco was gone. My doctor said cannabis doesn’t cause copd at all and is available at 18 yrs old in our red state instead of 21 like tobacco.
I actually just did a search…. Found tons of articles from medical journals (and the like). Picked one at random. In short the belief is that heavy MJ smoking will cause lung damage and possibly COPD, but there was no conclusive data that occasional or light use caused or contributed to pulmonary diseases. For what is — or isn’t — worth.