No one's studying this from a medical standpoint that I know of. But of course people can get high from secondhand smoke. For one thing, anyone in a confined space isn't just breathing in exhaled smoke that's already passed through the active smoker's lungs. They're also breathing in primary smoke from the joint (or whatever) is being burned nearby. Flight attendants got cancer from secondhand cigarette smoke, or at least they did back when smoking was routinely allowed on airplanes. The atmospheric smoke contains the same crap that active smokers are breathing in. Plus exhaled weed smoke doesn't come out stripped of its active ingredients. So people who are in the same vicinity as smokers are getting two types of exposure that could lead to getting high.