Subject: After smoking for 25 years, can quitting have negative effects?

I have been a witness to a few people quitting smoking after 20+ years who had 
not developed lung / pulminary / cancer diseases until after quitting. Is it at 
all possible that some humans after developing a 20 year tolerance to tobacco 
smoke have now intergrated these chemicals as part of their normal structre?
When the lungs try to so rapidly to repair themselves, can it be to much for 
some immune systems to handle? I have never seen anything published on this or 
the Negative effects from QUITTING smoking. Your thoughts are appreciated.

Re: After smoking for 25 years, can quitting have negative effects?