Im sure you're aware of this paper but Im wondering where you think they got this wrong. If i mess up let me know. its super late here.
Chemical analysis from a few flavors tested positive for a chemical (diacetyl) that can cause irreversible lung tissue damage (popcorn lung). This was found by researchers from Harvard supported by the national institute of health. The NIH is a government biomedical research arm. So I wouldn't say that source is super corruptible.
39/51 e cig vapors were found to have above limits of detection (LOD) of diacetyl.
NIOSH STEL (short term exposure limit for workers 15 min) for diacetyl is 0.025 ppm. The ACGIH STEEL is 0.02 ppm.
Resting breathing, is about 12 mL/kg. Lets say average weight is 65 kg. So thats 780 mL each breath. Adults do about 12-30 breaths per minute. Thats about 9.4 L a minute.
a 15 minute working exposure is about 180-450 L of air exchange for an average adult that weights 65 kg.
Diactyl MW 86.09g
simple math ideal gas law. Assuming temperature, pressure is close to normal ish room conditions and diacetyl is an ideal gas we can simplify the equation kinda. You can make better equation but i chose not to.
0.025 ppm * 86.09 g / 24.45 L = 0.08803 ug/L
So the lung is likely getting exposed to 180 L x 0.08803 ug/L = 16 ug in a total of 15 min (low end estimate)
now 16 ug/15 min is a max worker exposure limit by law or 3 ug/ 8 hours. They are probably calculating that 1 in 1000 to 10000 people will have an adverse reaction to diactyl at this level. If you do smoke ventilation can help those around you breathe.
out of the 39 flavors from an entire liquid batch of one flavor about 6 flavors had an estimated amount greater than 16 ug. most of them were from 'cocktail' flavors
are you going to smoke a full e cig in 15 min? (I honestly dont know) are you going to pick a bad flavor?
It seems that it is potentially significant for your health to frequently inhale a product containing diactyl concerning it may lead to permanent irreversible damage. But you're smoking so you already know its bad for you.