What is vaping? What are e cigarettes? Is it as harmless as it is made out to be? The truth is many e cigarettes contain nicotine, a highly addictive substance that can affect brain Lung Damage From Vaping Resembles Chemical Burns, Report Says The New York Times Vaping may seem harmless, but many products contain nicotine, toxic chemicals, and ultra fine particles that can damage the lungs and heart. For teens, nicotine can also affect brain development, attention, mood, and With and Without Nicotine, Thirdhand Chemical Residue from Vape Aerosols Impacts Anxiety, Memory, and Neurons Thirdhand Smoke Resource Center Vaping 'can damage vital immune system cells'