American forces in Vietnam begin using Agent Orange to remove foliage that has provided enemy cover, exposing U.S. troops to the chemical in the process. In use until 1971, the defoliant will cause widespread illness and prompt numerous legislative battles. The federal government will later direct the then-Institute of Medicine to issue reports every two years to assess the risk of both cancer and non-cancer health effects of the toxic herbicide. The report, “Veterans and Agent Orange,” is first published in 1994.