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 Health Risks of Secondhand Smoke and Aerosols Factsheet US EPA Study suggests switching from smoking to vaping indoors may reduce children's secondhand exposure to nicotine Secondhand vape exposure: Risks and side effects Secondhand Smoke and Electronic Cigarette Aerosol Resources US EPA Effect of second hand fumes from vaping on young lungs