There are several errors in the Harvard Medical School Advisor (HMSA) answer to the question. First, HMSA apparently misread the article, "Personal Review: Electronic cigarettes: miracle or menace?" published 19 January 2010 in the British Medical Journal. Authors Flouris and Oikonomou reported that New Zealand recommends use, the study from Greece was neutral and only the FDA report expressed concerns. Second, the HMSA incorrectly states, "the e-cigarettes all deliver an array of other chemicals, including diethylene glycol." The HMSA apparently relied upon the FDA's misleading press release instead of consulting the "Final Report on FDA Analyses" (
http://www.fda.gov/downloads/Drugs/ScienceResearch/UCM173250.pdf). The report reveals that the chemicals of concern were found only in the liquid, but in amounts too small to present a health hazard. No harmful substances were detected in the vapor. In the Journal of Public Health Policy, Kahn and Siegel reviewed 16 studies that "characterized, quite extensively, the components contained in electronic cigarette liquid and vapor using gas chromatography mass spectrometry (GC-MS)." One of these studies was the FDA's "Final Report." The authors concluded, "a preponderance of the available evidence shows them to be much safer than
tobacco cigarettes and comparable in toxicity to conventional nicotine replacement products." There is no evidence that the vapor contains any harmful substances, and more importantly, no evidence that anyone has been harmed by using e-cigarettes. In fact, users are reporting improved health. Most report elimination of all desire to smoke. Thus the fear that e-cigarettes will entice former smokers back into tobacco smoking is totally without basis. Success rates for FDA-approved nicotine replacement products that are recommended by HMSA range from 2% to 7%. The success rates for complete smoking cessation by switching to e-cigarettes range from 31% to 79%. Caveat Emptor, indeed!