Is it true that e-hookahs are safe to smoke?

E Hookahs: I had to look up what an ehookah is. It is an electronic cigarette or pipe that uses high temperature rather than combustion to vaporize tobacco and other substances. While it is true that there is less tar and carbon monoxide and other combustion products, i'm not sure that even the vaporization of other substances is healthy. Particulate matter in vapor can cause damage to lungs too.

E-hookahs not safe.: We're learning more and more that e-cigarettes and such are actually not safe alternatives to the real thing.