Scripps Health E cigarettes remain the most commonly used tobacco product among middle and high school students in the United States, according to the Instagram E Cigarette Poisoning Children's Safety Network E Cigarettes and Lung Health American Lung Association Bonne Vap Hauconcourt Magasins 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.