The reality is that putting stuff in your lungs is always going to be worse than not doing it. What's not always made clear is the comparison with bits of burnt dead plant vs. vapour. The effect on lungs has received far less attention than studies that look at emissions in the lab (often obtained at wattage levels that no vaper would use)..
This study that actually looks at the effect of vapour on the liquids that naturally work as part of the respiratory system finds that it's a pretty safe way to stop smoking.E-Cigarette Vapor and Critical Lung Function (from the post at BioMed Central)
"Results of the study found that e-cigarette vapor, regardless of its flavoring, does not affect the ability of surfactant to reduce surface tension. In contrast, conventional cigarettes significantly inhibited the ability of surfactant to reduce surface tension upon compression. We found that adverse effects of cigarette smoke on surfactant were induced by tar, which is the product of burning, and other major components of cigarette smoke (nicotine, acetaldehyde, and isoprene) did not cause surfactant disruption. This observation explains why e-cigarette vapor does not inhibit surfactant function, since e-cigarette involves vaporization, but not burning."Question is, of course - will mainstream media cover it? Nope - too boring.