Great reading.... https://www.rcplondon.ac.uk/file/3563/download?token=uV0R0Twz IMHO,one of the many highlights.... "8.5.1 Health harm As e-cigarettes have been in widespread use in the UK and most other countries for less than a decade, the health effects of long-term use are as yet unknown. As outlined in Chapter 5, there is very little evidence that short-term use of e-cigarettes causes any appreciable harm to users or to others, but information on long-term health effects of repeated and sustained inhalation of e-cigarette vapour is of necessity limited to inference, based on knowledge of the vapour’s constituents. The oxidant, particulate, carcinogen and other toxin contents summarised in Chapter 5 would be expected, from first principles, to increase the risk of lung cancer, COPD, cardiovascular disease and other diseases caused by smoking, but at much lower levels of risk. For the less common health sequelae of smoking,11 levels of increased risk are likely to be negligible. The risks attributable to long-term inhalation of nicotine in isolation from tobacco smoke, and of the propylene glycol, glycerine and other components unique to e-cigarettes, are also uncertain but likely to be low. The health harm to long-term users of e-cigarettes is therefore likely to be marginally greater than for those who use conventional NRT. Harm to others from vapour exposure is negligible (see Chapter 5). The effects of maternal use on the fetus are unknown but, on the grounds of the very low levels of toxins in vapour, are probably close to those of NRT. Accidental poisoning in children from ingestion of e-cigarette solutions, which has been reported and typically results in nausea and vomiting,34 are preventable through the use of childproof fasteners."