LEVELS OF SELECTED CARCINOGENS AND TOXICANTS IN VAPOUR FROM ELECTRONIC CIGARETTES (Goniewicz et al, Tobacco Control 2014; 23(2):133-139).

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Electronic cigarette vapour was analysed for a variety of toxicants, including carbonyls, volatile organic compounds, tobacco-specific nitrosamines & metals.  Toxicants were much lower than in cigarette smoke (particularly levels of acetaldehyde).  However, this was an ex vivo study & did not measure harmful constituents in the lung.

Summary: E-cigarettes as a harm reduction strategy among smokers unwilling to quit warrants further study. nticoagulation as a treatment for PAH.