Does secondhand marijuana smoke affect you?
The reported "contact highs" from secondhand marijuana smoke are almost certainly a placebo effect. It is difficult to get enough secondhand smoke to get a measurable amount of the active ingredient. In actual experiments, they had to lock people in a small closet and pump in so much smoke that they actually had to wear goggles to stay in the room before the people would test positive for marijuana. ---------------------
It does affect you, and part of that has to do with genetics. Some people don't seem to be affected much, but I am very sensitive to marijuana smoke and have gotten high from my neighbor's smoke. She smokes very strong pot, and I don't know if I'd test positive, but it certainly affected my driving. One time I took a benadryl and didn't know pot smoke was coming in, and the benadryl added to the effect of the pot, and I got much more sleepy than usual from taking a benadryl.
I'm allergic to marijuana, so I've gotten coughing and asthma from second-hand smoke, and also I get painful sores on my head when the neighbor smokes it. It gives me mood swings, then I smell her pot half an hour later. One time I was very, very tired from the marijuana smoke coming in, then when it wore off, my heart beat really fast for a couple of hours. After that, I read that a man in England had died from a heart attack after smoking marijuana, because it affects your heart rate when you smoke it and when it's wearing off. This kind of thing never happened to me in the 1960's, but maybe there's something in some new varieties that has been increased. There are at least 66 cannabinoids, and there isn't a lot of testing for them in the new varieties, just usually THC.
The book "Marijuana: What's a Parent to Believe," by Cermak describes its physiological effects.
not exactly an obvious question but i will answer what i know on the subject.
Is it harmful? arguably yes but in its pure form it has a low neuro-toxicity level and also very low cancer causing chemicals, if in a joint with tobacco the tobacco is far more harmful and more of a worry.
Will it get you high? it could in very large doses or in an enclosed space over time however a small amount is unlikely to cause any noticeable effects and anything a person feels from second hand smoke is usually a placebo effect brought on by an expectation of a feeling from being in close proximity to a drug.
Should you worry? in short no not really, whether inhaling 2nd hand cannabis smoke or producing it its unlikely to be an issue for you or other people.