E cigarettes & vaping statistics & facts Allen Carr's Easyway Vaping Produces Far Less Second Hand Nicotine Than Smoking Respiratory Therapy Vaping has become common, but it's important to know what you're inhaling. Many e cigarettes contain nicotine, heavy metals like nickel and lead, and chemicals that can harm your lungs and overall health. A Comprehensive Review of the Harmful Compounds in Electronic Cigarettes