The reading is dry, dry, dry but here goes ---
The information most relevant in their landmark report from the Royal College of Physicians are on pages 79-86 on this document ---->>>>
Nicotine without smoke
The Royal College of Physicians summary says this:
Analysis of vapour generated by e-cigarettes has identified a number of potentially harmful constituents delivered alongside the nicotine and other
e-liquid components. These include volatile organic compounds, carbonyls, aldehydes, tobacco-specific nitrosamines (TSNAs) and metal particles, but all at much lower levels than in cigarette smoke.50–64 Levels of formaldehyde and other aldehydes can be relatively high when vaporisation occurs at high temperatures,65,66 although in practice this overheating generates an aversive taste known as a ‘dry puff ’, which vapers avoid.66,67 Recent reviews of the health effects of toxins inhaled during normal use of e-cigarettes have expressed concerns over potential adverse effects based on the presence of these contaminants,68–70 but not their levels, which are generally the more important determinant of toxicity. In normal conditions of use, toxin levels in inhaled e-cigarette vapour are probably well below prescribed threshold limit values for occupational exposure,71 in which case significant long-term harm is unlikely. Some harm from sustained exposure to low levels of toxins over many years may yet emerge, but the magnitude of these risks relative to those of sustained tobacco smoking is likely to be small. However, consideration of the potential harm of long-term e-cigarette use should serve as a guide to evidence-based product development, regulation and monitoring.
Just "nicotine" itself is only habit forming, more along the lines of caffein - it is the other alkaloids in tobacco that make cigarettes and other products so highly addictive
The Royal College of Physicians says this about nicotine:
Nicotine is not, however, in itself, a highly hazardous drug (see Chapters 4 and 5). It increases heart rate and blood pressure, and has a range of local irritant effects, but is not a carcinogen.37 Of the three main causes of mortality from smoking, lung cancer arises primarily from direct exposure of the lungs to carcinogens in tobacco smoke, COPD from the irritant and proinflammatory effects of smoke, and cardiovascular disease from the effects of smoke on vascular coagulation and blood vessel walls. None is caused primarily by nicotine.
