E cigarettes found to cause change in mouth bacteria which could lead to gum disease or oral cancer E cigarettes may cause cancer, new study finds E cigarette vapour contains two cancer causing chemicals, study says Clinical Oncology Society of Australia concludes E cigarettes are likely to cause lung cancer and oral cancer Stanton Glantz blog Health Risks of E Cigarettes and Vaping American Lung Association E Cigarettes: Know the Health Risks Department of Health