Secondhand Smoke and Electronic Cigarette Aerosol Resources US EPA 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 Secondhand e cigarette vape smoke exposure increased in last 4 years, contain harmful toxins: JAMA Network study ABC13 Houston Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London