Symptoms Of Second Hand Vape Smoke Secondhand smoke is harmful to those around you, putting them Secondhand Smoke Social Media Message Library Tobacco Education Clearinghouse of California 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% Should I Be Concerned About Secondhand Vaping?