Secondhand exposure from vaping marijuana: Concentrations, emissions, and exposures determined using both research grade and low cost monitors ScienceDirect About one in four adults in California report being exposed to secondhand smoke or vape in the past two weeksoften on sidewalks, at home, and in recreational spaces like parks and beaches. Does Vaping Cause Secondhand Smoke? Secondhand Smoke vs Vape: What the Science Says