Use of e cigarettes after quitting smoking increases lung cancer risk Cancerworld Magazine Health Effects Vaping Information, Solutions & Interventions Toolkit Stanford Medicine E liquide cigarette elecronique sans propylene glycol Vegetol Pure E cigarettes increase harm to smokers, so should not be promoted as a harm reduction strategy (in 10 slides) Stanton Glantz blog Smoke without fire: What's the truth on e cigarettes? New Scientist