That’s why I was so interested in the study of smokeless tobacco users.
Anyway, I don’t mean the tar is the physical barrier, inflammation response plus common changes to the extracellular matrix should both result in a physical barrier. The compensative increased respiratory rate seems like it would offset reduced surface area, but these changes are more complicated than that.
Also, it’s increased risk of detected infection, but patients without symptoms are rarely tested for viral disease at this scale. That makes comparisons very tricky.
Anyway, I don’t mean the tar is the physical barrier, inflammation response plus common changes to the extracellular matrix should both result in a physical barrier. The compensative increased respiratory rate seems like it would offset reduced surface area, but these changes are more complicated than that.
Also, it’s increased risk of detected infection, but patients without symptoms are rarely tested for viral disease at this scale. That makes comparisons very tricky.