It’s just coming from the source foods, yes, and Americans already eat these minute quantities of heavy metals on a regular basis from other sources. This paper

It’s just coming from the source foods, yes, and Americans already eat these minute quantities of heavy metals on a regular basis from other sources. This paper makes some attempt to put the numbers in context: https://pmc.ncbi.nlm.nih.gov/articles/PMC7509468/ https://pmc.ncbi.nlm.nih.gov/articles/PMC7509468/