I think any time a new material starts to meaningfully accumulate in our bodies, our food sources, our oceans, etc, we should at least go with caution. The default stance should be caution, not fearlessness.

>fearlessness

More like flippancy, even hubris.

The approach you advocate is essentially the EU's precautionary principle. [1]

[1] https://eur-lex.europa.eu/EN/legal-content/summary/the-preca...