Yeah this is kinda "well known" in the protein powder circles: https://www.health.harvard.edu/staying-healthy/the-hidden-dangers-of-protein-powders#:~:text=Rese

Yeah this is kinda "well known" in the protein powder circles: https://www.health.harvard.edu/staying-healthy/the-hidden-dangers-of-protein-powders#:~:text=Researchers%20screened%20134%20products%20for,cancer%20and%20other%20health%20conditions https://www.health.harvard.edu/staying-healthy/the-hidden-da.... (essentially condensing down milk products that don't have a large % of heavy metals but this gets condensed down and the heavy metals are more likely to stay behind - 200 liters of milk to make 1kg of protein powder).