The rise of teen vaping is worrying doctors worldwide. While e cigarettes were once marketed as a safer alternative, research shows they contain nicotine, heavy metals, and cancer causing chemicals that can damage developing Irish Cancer Society position on e cigarettes Irish Cancer Vaping and Lung Cancer Risks: What You Need to Know Parkway Cancer Centre Singapore Comparing the cancer potencies of emissions from vapourised nicotine products including e cigarettes with those of tobacco smoke Tobacco Control E cigarette vapor linked to cancer in mice National Institutes of Health (NIH) Teens inhale cancer causing chemicals in e cigarettes