I don’t know how it is elsewhere, but in the Netherlands (as per EU regulation) the limits of dangerous substances in food are determined according to the ALARA principle. For fish, the limits are a lot higher because otherwise fish would be blacklisted, there’s always more toxic substances in fish because they are caught in open water. The same open water where chemical corporations dump their waste streams containg mercury, PFAs etc. So according to our government eggs from your own chickens aren’t healthy because of PFAS*, but fish containing more PFAS is.

*Commercial eggs are fine, since these chickens don’t get to eat insects, snails or worms from the ground. These animals absorb PFAS from the soil.

Probably because most people aren’t eating shit like swordfish, shark, or giant mackerel regularly enough to be worried about it. The kinda fish most people eat daily has very little, if any, mercury. A lot of it is farmed and not caught wild where mercury is a problem.

Or you could do some light research to find out which kinds of fish have highest and lowest mercury levels?

My understanding is that the more you go in the apex predator direction, the more you’ll find mercury and other undesirable shizzle.