Ken_A;12470585 said:Huh? No studies?
How about
http://www.sciencedirect.com/science/article/pii/S0306460313003304
PLOS ONE: EffiCiency and Safety of an eLectronic cigAreTte (ECLAT) as Tobacco Cigarettes Substitute: A Prospective 12-Month Randomized Control Design Study
http://www.biomedcentral.com/content/pdf/1471-2458-11-786.pdf
You ca. Probably find one or two more in the link provided in my sig.