Chromium (Cr) is a heavy metal that naturally occurs in the Earth’s crust, and can be found in groundwater in either the trivalent, Cr(III), or in the hexavalent, Cr(VI), form. While Cr(III) is considered an essential trace element for the human body, Cr(VI) is potentially dangerous for human health although the type and intensity of the effect are still being investigated. The widespread use o...