Quote Originally Posted by beachguy in thongs
The longer breath-holding time significantly increased both percent retention of tar in the lung and the pre- to postsmoking rise in blood COHb, serum THC and heart rate, independent of puff volume and number. In contrast, the larger PV (tobacco) had no significant influence on these variables for the same amount of cigarette consumed.
May I ask where you got the piece of information?

And can you explain it in layman's terms?