The least to most harmful , according to science. Viewpoint: Is vaping a pathway to tobacco addiction or quitting tobacco altogether? It depends Genetic Literacy Project Glyphosate et cancer : un cas d'cole de la fabrique du doute What's in an E Cigarette? American Lung Association Genotoxic activity of glyphosate and co formulants in glyphosate based herbicides assessed by the micronucleus test in human mononuclear white blood cells ScienceDirect Boom In E Cigarettes Sparks Calls For Regulation