https://pubmed.ncbi.nlm.nih.gov/?term=copper Before 1967, there were only about 500 articles on copper. Before 1993, there were only 31,547 results. (1993 is an important year, as we will see later in the chapters on the RDA and tolerable upper human limit, set by the government in 1993) Before 1999, there were only 41,507 results. As of 9/30/21, … Continue reading Chapter 37: 143,153 Articles on Copper at PubMed.gov