I would also like to see any scientific long-term studies on vaping. ...but I just don't think they're out there since vaping is relatively new. Even the newest study from my neck of the woods (Drexel University, Philadelphia, PA) says that the largest missing thing is a long-term study of PG/VG effects on humans (since even because PG/VG is deemed safe in things like inhalers, nebulizers, and fog machines, the amounts we ingest from vaping is several orders of magnitude greater than those devices).