E cigarettes contain hazardous substances, addictive and harmful Second hand vaping exposure very low compared to second hand smoking UCL News UCL University College London If you vape, you inhale a lot of harmful substances. These can damage your heart and lungs. What You Need to Know About Vaping No, vapes aren't 95% less harmful than cigarettes. Here's how this decade old myth took off It's Not Just Cigarettes: Vape Residue Sticks on Surfaces Too Thirdhand Smoke Resource Center