Vaping nicotine and mental health Johns Hopkins Medicine Team Proposes Ways to Regulate and Better Manage E Cigarette Use Johns Hopkins Medicine 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. E Cigarettes: Perspectives, Regulation and Health Effects Nova Science Publishers Vaping and E Cigarettes ADAPP