Which of the following is a non-essentialmetal/mineral?

Lead Lead is not at all an essential mineral; rather it is toxic to the body. (Harrison I7/e Chapter e34. Heavy Metal Poisoning ) Harper gives a list of essential minerals along with their functions in the body. Essential minerals and their function Function Mineral Structural function Calcium, magnesium, phosphate Involved in membrane function Sodium, potassium Function as prosthetic groups in enzymes Cobalt, copper, iron, molybdenum, selenium, zinc Regulatory role or role in hormone action Calcium, chromium, iodine, magnesium, manganese, sodium, potassium Known to be essential, but function unknown Silicon, vanadium, nickel, tin Have effects in the body, but essentiality is not establislifd Fluoride, lithium May occur in foods and known to be toxic in excess Aluminum, arsenic, antimony, boron, bromine, cadmium, cesium, germanium, lead, mercury, silver, strontium