Analysis suggests e cigarette use may be linked to lower rates of smoking 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. Medical infograph. The infograph was developed by the Consumer Download Scientific Diagram The Dangerous Truth Behind E Cigarettes Advanced DDS Vaping harms your health Cancer Institute NSW