Secondhand smoke and secondhand aerosol Health Risks of Secondhand Smoke and Aerosols Factsheet US EPA In secondhand vape, scientists smell risk American Heart Association According to a Centers for Disease Control and Prevention (CDC) study, 40% of U.S. adults believe that children's exposure to secondhand aerosol from e cigarettes causes only some or little harm, and 5% Secondhand vape aerosol can contain particles and chemicals that may affect indoor air quality. Research continues to examine possible respiratory impacts.