Teens making dangerous changes to vaping devices U.S. e cigarette use stalls as health concerns grow: Reuters Ipsos poll Reuters 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 draw fans as states and FDA question safety The flavoring chemicals in e cigarettes are linked to a disease known as popcorn lung