E Cigs Are Going Tobacco Free With Synthetic Nicotine WIRED Vaping may raise cancer and heart disease risk, study suggests Medical research The Guardian Nicotine absorption from electronic cigarette use: comparison between first and new generation devices Scientific Reports E cigarette Vaping Q&A Allegro Pediatrics E Cigs & Oral Health: How Vaping Affects Gums & Teeth What's in an E Cigarette? American Lung Association