Re: We already know.
"Popcorn lung" is still out to jury.
No, it isn't. The jury came back in some time ago with a not guilty verdict.
While studies like Harvard’s are critical to fully understanding e-cigs, they too often have the opposite effect. Tobacco cigarettes, for instance, have also long been known to contain diacetyl — at levels over 100 times those found in electronic cigarettes — yet earlier tobacco studies found that even these levels were not enough to cause popcorn lung in smokers.