Secondhand Exposure to E Cigarettes Puts COPD Patients At Risk Respiratory Therapy 2nd Hand Vape Smoke Effects The Issues of Testing for Secondhand Smoke E Cigs and Second Hand Vaping: Dangers and Protections Health Risks of Secondhand Smoke and Aerosols Factsheet US EPA Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London Second Hand Vaping: Minimal Impact Compared to Smoking