http://www.prnewswire.com/news-releases/casaa-new-study-confirms-that-chemicals-in-electronic-cigarettes-pose-minimal-health-risk-218843731.html
Best Quote:
"By reviewing over 9,000 observations about the chemistry of the vapor and the liquid in e-cigarettes, Dr. Burstyn was able to determine that the levels of contaminants e-cigarette users are exposed to are insignificant, far below levels that would pose any health risk. Additionally, there is no health risk to bystanders. Proposals to ban e-cigarettes in places where smoking is banned have been based on concern there is a potential risk to bystanders, but the study shows there is no concern."