E cigarettes found to cause change in mouth bacteria which could lead to gum disease or oral cancer Health Effects of Vaping Smoking and Tobacco Use CDC Vaping likely to cause cancer: New research warns A major review led by researchers at UNSW Sydney says nicotine vaping may be linked to both lung cancer and oral E cigarettes: 'cancer risk close to zero' Bhekisisa Use of e cigarettes after quitting smoking increases lung cancer risk Cancerworld Magazine