I think one of the biggest issues in society today is that so much is changing so quickly, on a species level scale, that it's phenomenally difficult to isolate cause and effect for any thing that requires more than a 6 month controlled trial to show up on. It's not like you can just do an observational study on families of children who were not exposed to microplastics vs those who were, because the former group doesn't exist. And even if it did, what if the effect is something like leaded fuel, where it's only really measurable, and indirectly at that on a population level sample, decades after exposure?
Just think about how absurdly much has changed in the past 30 years in terms of consumption and lifestyle. Trying to figure out what might even possibly be causing something is just going to leave you with an endless series of "The evidence is inadequate to accept or reject a causal relationship between [a] and [b]."
I don't think we need exhaustive studies to know that using reactive chemicals that aren't found in nature for literally everything is a bad idea. if it's not been harvested with something with DNA, it's probably not a good idea by default
Just think about how absurdly much has changed in the past 30 years in terms of consumption and lifestyle. Trying to figure out what might even possibly be causing something is just going to leave you with an endless series of "The evidence is inadequate to accept or reject a causal relationship between [a] and [b]."