For one thing if you can smoke 9 joints on the way to work, you better look for another supplier. Another thing is it may stay in your system for 30 days or more and even longer in your hair, but the sensitivity on these tests are usually set for 2 weeks or even less, so second hand most likely won't be positive. I know several who have smoked two weeks prior to a ua and came up clean. I remember way back around 1972 there was an attempt to legalize it and did have alot of support but failed.