Tin sources and trade in ancient times Bantu culture of Zimbabwe are known to have actively mined, smelted and traded tin between the 11th and 15th centuries AD . Tin deposits exist in many parts of South America, with minor deposits in southern Peru, Colombia, Brazil, and northwestern Argentina, and major deposits of exploitable cassiterite in northern Bolivia. These deposits were exploited as early as 1000 AD in the manufacture of tin bronze by Andean cultures, including the later Inca Empire, which considered tin bronze the "imperial alloy". In North America, the only known exploitable source of tin during ancient times is located in the Zacatecas tin
Antimicrobial copper-alloy touch surfaces product stewardship of antimicrobial copper alloy products. CDA must ensure that manufacturers promote these products in an appropriate manner. Manufacturers must only promote the proper use and care of these products and must specifically emphasize that the use of these products is a supplement and not a substitute to routine hygienic practices. EPA mandated that all advertising and marketing materials for antimicrobial copper products contain the following statement: Antimicrobial copper alloys are intended to provide supplemental antimicrobial action in between routine cleaning of environmental or touch surfaces in healthcare settings, as well as in public buildings and the home. Users