Metals

Several metal ions such as potassium, sodium, magnesium and calcium are necessary to sustain biological life. Traces of metals are necessary for optimal growth, development and reproduction. They function mostly as catalysts for enzymatic activity in human bodies. However, all essential traces of metals become toxic when their concentration becomes excessive. Commonly this happens while the levels exceed through 40- to 200-fold of those needed for correct nutritional response. Some of the metals are toxic such as mercury, cadmium, lead, chromium, silver, aluminum, selenium, arsenic and barium. These metals could cause chronic or acute poisoning and should be eliminated from the drinking water if probable. For example mercury and its compounds are very toxic to plants, animals and humans. These compounds bioaccumulate in the food chain and can cause serious acute and chronic disorders.