Some natural aquifers are contaminated with pollutants. While grass fed farms do quality control to keep habitats free of toxins. The opposite can also be true. It all depends upon circumstances.

I think wild meat is healthy, but deer don’t have enough fat to really sustain a healthy human. Unfortunately Mammoth are gone, and the US govt wiped out the bison in order to starve out the Native Americans…so beef is a necessity I think.