Secondhand vape plumes could form lung damaging radicals American Chemical Society What harm does second hand fumes from vaping cause to young lungs? Medical experts want to know ABC7 San Francisco Secondhand smoke is harmful to those around you, putting them at risk for serious health issues. Protect your loved ones from the dangers of secondhand smoke by getting started with 802 Quits Do cigars cause thirdhand smoke? Thirdhand Smoke Resource Center Sitting somewhere when a cloud of cotton candy vapor washes over you? If you can smell the sweet scent of a vape, that's not a great sign.