I was hanging out,
smoking a bowl with a few of my
geek friends a while ago, and one of them who chose not to
partake made some sort of a comment about getting a
contact buzz. This sparked a long discussion about whether or not a contact
buzz was actually possible in this situation. I don't remember the exact
math we figured out (I was
stoned, after all), but we pretty much figured out the quantity of
smoke you would have to
inhale to get a buzz, compared that to the relative
saturation of
THC when taking a
hit from the
pipe, compared to that suspended in the air (most of which is post-exhalation (
second-hand)).
We came to the conclusion that you would have to smoke about 1/8 of an ounce in a room no bigger than a mid-size car for a "contact buzz" to be at all possible (and that's for someone with a very low tolerance). Most of the time when people speak of this phenomenon, they are really referring to a psychosomatic response.