Also to be clear, at no point did I say 100% about anything. Please do not attempt to put words in my mouth, or to fight a straw man. We can all acknowledge that empirical studies don't give 100% certainty about anything.

But it does also seem fundamentally problematic for us to make substances or materials ubiquitous in our environments faster than we can study them. We then also arrive at a methodological problem, where, for example we cannot meaningfully study whether long-term low-level exposure to PFAS are causing impacts on fertility in part because there is not a population that hasn't already had that exposure.