I've not seen our cast iron or carbon steel pans flaking off into food like I have seen with Teflon. I doubt there is much of anything harmful coming off during cooking -- not any more harmful than the cooked food itself likely.
I too see a lot of sensible awareness towards PFAS, but often wonder how many (if any) good ol' PAHs get thrown into your food from the fat seasoning of non-coated pans.