Blu electronic cigarette bad for health?

Yes: the question isn't whether they are harmful - nicotine is addictive, causes blood vessels to constrict and reduces blood flow to heart, brain and vital organs, and is what causes the vascular problems related to smoking. There are less "tars, " but nobody knows what the propellant (propylene glycol), flavorings, preservatives and other additives do, either short-term or long-term at this point.