Infographic: E cigarettes & Cardiovascular Disease World Heart Federation Don't be foolede cigs or vapes may be less harmful than cigarettes, but less harmful doesn't mean safe. Vapes can contain harmful substances including nicotine, heavy metals like lead, volatile organic compounds and Tobacco free' e cigarettes turn liquid nicotine into a vapor The Blade Evidence builds that e cigarettes help smokers quit The Boston Globe E Cigarette and Endothelial FunctionA Critical Review of Preclinical Studies Chemical Research in Toxicology