Toxicological Effects of E Cigarettes on Cells, Animals, and Humans and Mechanisms of Toxicity Springer Nature Link 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 and Pregnancy Maternal Infant Health CDC What you should know about vapes and e cigarettes