How long does marijuana stay in the air?

Answer 1

Depends on how ventilated the air is, and how much is smoked. Usually up to an hour for light/moderate smokage, and possibly up to two hours for heavy smoking.

I used to smoke in my room daily after my parents went to bed. They didn't approve of my habbit, and certainly wouldn't be okay with me smoking it, or anything for that matter, in my bedroom. They never suspected a thing, except when I tried to smoke cigarettes in my room.