Heavy metal poisoning manganese

Iron and zinc are heavy metals but nature has selected them for vital functions. Almost one-third of all known proteins are metal proteins. They may contain iron, zinc, copper, cobalt, molybdenum, and/or manganese. With this in mind it is not fair to equate heavy metal with environmental poison . It is a part of the dynamics of life that elements, even heavy metals, that are available in the environment in safe amounts have been used for the development of organisms. 

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