As a healthcare professional, I'm done following this Eissenberg guy. A "clinical Study" with an N(sample size) of 32 proves nothing. He also seems to keep proving (or trying to prove) that ecig usage is tantamount to some type of Placebo effect. He uses ecig brands that I never heard of (NPRO-Hydro EC??) and allowing cigarette users to use their "own brand" (which means they'll all be different) is a terrible control method.
His study methodolgy with regards to the actual vaping protocol also shows he knows next to nothing about how real word vapers actually vape.