Lead is a metal that in its pure form is indestructible. Manufacturers use lead in many ways; Batteries, Paints, Ceramics, Building materials. However the bluish-gray metal can be found in plants, the air and water. It is in the drinking water that most of the problems with lead metals exist since about 15 to 20 percent of the lead humans consume every day comes from the drinking water. And about 75 to 90 percent of the lead in humans is found in the bones and teeth. High levels of lead can cause many health problems. Lead poisoning can cause serious problems with the nervous system in children and adults. And while studies have not been conclusive about the link between lead and cancer, the Environmental Protection Agency (EPA) has listed lead as a probable carcinogen. Lead has been linked most often with lung and stomach cancer.