Can being in a room where others are smoking pot cause you to breathe it in and have a small amount in you?

Smoking pot: Yes. This is similar to second hand cigarette smoke that effects everyone in the home where smokers smoke.

Debatable: Second hand smoke is very unlikely to cause significant blood levels. Some have even looked at this in a closed environment like a car. Most urine tests have cut off levels that could not be likely reached by second hand smoke. It is unlikely this argument would work in any legal proceeding.