I am a co-author on this poster (Kistler). Many of the flavors that tested positive for DA were in fact advertized as DA-free. AP is a DA replacement, but it has been shown to be just a toxic as DA recently.
As for smokers not being known to get BO, there is still much we don't know about BO. It might be that DA or AP along with smoke other lung problems occur (COPD is fairly common, and could be misdiagnosed BO). There is evidence that BO is auto-immune, rather than a purely chemical process, and perhaps other physiological/genetic factors must be also present for the disease to take hold. One thing is clear, if you have BO and get a lung transplant, it is likely that the new lung will also get BO. BO might for some be a very slow and cumulative process, barely noticeable at first, but irreversible. That shortness of breath will never get better. In others it might take several years to develop, or it might take much less time. It is rare and not completely understood just yet.
Also, we only measured the presence and concentrations of these compounds. We have not done toxicological studies. So while these are known inhalation toxins, we did not and cannot in this particular study say that BO will occur in vapers using these particular liquids or flavors. That is for another study we are hoping to do in the future. This is a more complex issue, since across vapers there are variances in wattages, flavor %, even vaping habits. And also all the other unknowns about BO itself, independent of how the DA or AP is delivered.
In tobacco smoke these compounds are from the combustion process, and thus with smoking they are unavoidable. But this is not so with e-liquids. They are ingredients of flavors that do not have to be added, and verified as not being present. Thus they are avoidable. We believe that until rigorous toxicological studies are done by using ecig vapor that flavors not containing these compounds, and verified experimentally, should be made available. Indeed, this solution is already in the works in both the e-liquid and flavor industry. I cannot say time frames, but the wish is there on both sides.
One should always read science critically, and we are very open to questions and criticisms. Indeed the paper which should be out soon on this study went through considerable peer-review. But while the results of this study are not positive, especially to someone who loves creams and custard vapes, our goal is to make vaping as safe as possible. We also wanted to make sure this issue, which was already getting a fair amount of buzz in the online community, was studied by objective scientists who have the safety of vapers in mind, with high-level established methods, rather than those that would be all too happy to spin the results into an argument for banning.
