It's not even close to conclusive, I think you'd be hard pressed to call it science. Whenever you read these "studies" there is so much defensive language and obvious outright lies, you can tell it is a propaganda piece.
> "potentially as harmful"
> "may contain"
> "have as much potential to cause DNA damage"
> "found that vapor from non-nicotine e-cigarettes caused as much DNA damage as filtered cigarettes" (at best they have a theory)
> "whether they serve as a gateway for future tobacco smokers remains the subject of much debate" (if you call lobbyist propoganda "debate")
> "new metabolites that have the potential to cause DNA damage are formed"
> "The device is unique in that it converts chemicals into their metabolites during testing, which replicates what happens in the human body, Kadimisetty says." (Does it? Is this scientifically confirmed with high certainty?)
> "Bioassays currently used to determine the genotoxicity of environmental samples may be more comprehensive" ("May" be? If you are speculating on that, then how do you know that the results from these tests are trustworthy, as you are claiming?)
> "There are potentially hundreds of chemicals in e-cigarettes that could be contributing to DNA damage, Kadimisetty says." (Well, depends on your definition of chemicals)
> "Rather than test for all of them, the UConn team targeted three known carcinogenic chemicals found in tobacco cigarettes." (Oh? Which ones? And what was the source of the ejuice used for testing?)
EDIT: The three chemicals (thanks xaedes): https://news.ycombinator.com/item?id=14539062
B[a]P: Benzo[a]pyrene
NNK: 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone
NNN: N-Nitrosonicotine
I haven't a clue what these are, and in which component of the juice (PG, VG, nicotine, flavor) would contain them....anyone?