Guess.
This place, ECF, is full of Vapers, since more than a decade, and not one of them has reported a lung sickness related to
vaping in all this time.
It is an enormous point of strenght; its only weakness... It is too obvious. But has the strenght of a verified statistics, when all at sudden, in a restricted group, a misterious illness pops out, it can easily prove it isn't related to traditional
vaping, but there are other things to take into consideration.
My 2 cents.