Consume Product

With store bought, you never know. Always buy directly from the farm if possible, or go shoot something in the forest yourself. Sure it's a lot more work, but there's also plenty of local slaughters willing to help in exchange for money, or some of the meat.

As for poison in nature, do study the area for potential pollution sources, wind farms for instance means the animals can be full of microplastics. Be sure to donate blood to get rid of those plastics, or at least reduce the damage.