Will marijuana affect you if you were in same area it is being smoked?

Yes. You probably won't get very high yourself, but you can get enough to fail a drug test if you are in an enclosed space such as a car or small room.

Back in the '60's we used to talk about "contact highs," when people acting goofy around you start you doing the same thing, even though you were not smoking. There is a lot to that idea, as well, since we know that group pressure also modifies behavior.