Ill necro post just to comment on this. when they are testing vaping effects, i believe they use the same scale as the epa does for air pollutants. so far they have not found vaping to be any more harmful than the air you breath, especially in areas where u r constantly receiving air quality warnings.
Now two caveats. technically, if u r using a vape in a polluted air environement, technically u r getting a double dose of pullutants, polutted air plus the vape pollutant (for lack of a better term. Unless somehow the coil burns off the air pollutants).
This bring up an interesting question. what is the air quality in the lab? rutgers is in jersey, near new york, if they are using semi polluted air to run thru a vape, of course the result is vape mixed with the polluted air.
So far johns hopkins has yet to find any higher level of epa rated air quality problems with vapes over their own standards about what is safe to breath.
None of anything is about health, and anti vaping studies are a great way to get grant money from anti-vape organizations, which is how most of these scientists get paid. its all about money.