Understanding the Hidden Health Risks of Vaping UL Research Institutes 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. Health Problems Caused by Secondhand Smoke Smoking and Tobacco Use CDC Chemical characterisation of the vapour emitted by an e cigarette using a ceramic wick based technology Scientific Reports Restored CDC Youth and Tobacco Use Smoking and Tobacco Use CDC