Quote Originally Posted by DeepFriedBrain
A study done by a group of doctors in Canada at Dalhousie University, concluded that more than 90% of the THC is absorbed into the lungs within the first seconds of inhalation. Another study confirms this, but they put their number at 95% absorption. The 5-15% of THC that isn't absorbed is due to THC loss in trace smoke, or smoke that never enters the lungs.

This doesn't sound right.
According to these reports 90-95% of the THC is absorbed within 3-5 seconds. Now if I were to vaporise a bud and hold the vapor in for 3-5 seconds and then exhale, I get a huge cloud of vapour ( THC, terpines, etc ) expelled from my lungs.
If I hold it for 50 seconds( with vapor you can do this), I get very little coming out when I exhale.
If all the THC is absorbed after 3-5 seconds, then what the hell am I exhaling?

Just because a doctor said it, it doesn't mean it's true.
This thread and you remind me of the government and how they try to twist test results. The results you just posted are saying that the other 5-15% of THC is smoke that never entered the lungs. Smoke that either slipped out your mouth while hitting it, smoke that stayed in your mouth because you took a huge hit and didn't think to leave a couple seconds of breath to clear your mouth/throat, smoke that sat in your throat for the previous reason. Or could be something else. Holding a hit for 50 seconds is ridiculous. You are cutting off oxygen to your brain and probably doing more damage than weed will EVER do. If this other 5-15% of smoke is so precious to you then try taking a big hit, blowing like 1/3 out, inhale again, blow 1/3 out, keep doing that until you are blowing no more smoke. This is probably just as bad as holding it and letting the tar coat your lungs but at least your brain isn't being deprived of oxygen! You damn fool.