I will buy grass-fed beef from NZ and Australia, but not from the US because of how often it contains toxins (probably mostly heavy metals, hard to say because

I will buy grass-fed beef from NZ and Australia, but not from the US because of how often it contains toxins (probably mostly heavy metals, hard to say because I never had any analyzed, but I am unusually sensitive to heavy metals) in my personal beef-buying experience. Grain-fed US beef doesn't have the problem. My guess is that there has just been much more industrial activity in the US than in Aus and NZ.