While there are numerous metals that are necessary for healthy body functions, high levels of these essential metals can be harmful to health. Many dissolved metals that contaminate water supplies can be acutely or chronically toxic. Contamination levels vary widely by geographic location and water source, spurring the need for localized testing. Exposure to even minute amounts of certain metals such as lead and mercury through drinking water has been linked to developmental delays and deficits in learning abilities in children, as well as high blood pressure and kidney problems in adults. If necessary, reverse osmosis (RO) systems or Kinetic Degradation Fluxion (KDF) filters can remove dissolved metals at the point of delivery.