> But, as the article points out, the impacts of these plastics in real life is completely unknown, and considering that these plastics have literally been in use for the better part of a century, that puts a pretty strict upper limit on how bad they can be. If they were more than trivially harmful, we would know by now.
I think you might be overestimating the degree that science has the power to answer these questions, especially when it can't be tied to some obvious grant funding source.
We can't even be sure of the link between CO2 and cognition. If you look at the studies, the bulk of them are done by the Navy and they're not super applicable to office/school settings. Of the ones remaining, most of them are too underpowered to convincingly demonstrate either way and the meta analysis is all a mess. This should be one of the most gotcha easy questions we can formulate but because nobody directly makes a high ROI from funding it, Scientists scrabble around for funds.
There was the famous, now retracted study that showed that judges were much more lenient on cases after lunch than before, that was taken down on methodological grounds. But notice that it wasn't taken down because it was inconsistent with previous literature on other fields and the impact of lunch on decision making... because there was no previous literature. We all know there's some pretty sizable effect that lunch has on cognition and the workplace is full of tips and heuristics about how to avoid that post lunch slump or what tasks to schedule after lunch. Plenty of anecdata that there's a effect but again, no money to scientifically characterize the effect.