In recent years, the number of e cigarette users worldwide has sharply increased, with many believing that vaping is less harmful than smoking traditional cigarettes. However, health experts are warning of its negative E Cigarettes and Pregnancy Maternal Infant Health CDC Researchers Find Toxic Metals in E Cigarette's Johns Hopkins Bloomberg School of Public Health Vaping and the Brain: Effects of Electronic Cigarettes and E Liquid Substances The Journal of Neuropsychiatry and Clinical Neurosciences