Secondhand smoke and secondhand aerosol How secondhand smoke, thirdhand smoke & vaping affects kids Millions of people are exposed to secondhand smoke every day. People living in multi unit housing are some of the most exposed. The only way to fully protect people from secondhand smoke at 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. Tobacco Smoke, Vaping, and Asthma AAFA.org