ABSTRACT
In the US, lead is found more frequently than cadmium in drinking water systems, primarily because of the wide use of lead service pipe in many of the older cities. The Environmental Protection Agency has established maximum contaminant level for both lead and cadmium and is currently reviewing scientific data to determine if these limits provide for adequate margins of safety. The relationship of disease status and calcium in drinking water, however, was more consistent than the relationship with magnesium in drinking water. Natural sources account for much of the arsenic and selenium found in drinking water supplies, although the presence of arsenic in soils can be related to its use as pesticide. Ingestion of excessive fluoride in drinking water can result in mottling of teeth and dental fluorosis in children, and increased density and calcification of bone (osteosclerosis) and skeletal fluorosis in adults.
