Lead See Also: Chemical Elements Metallic Element, one of the earliest known Metals, used by the ancient Egyptians and Babylonians. A poor Conductor of Heat and Electricity, lead is Silver-blue, dense, relatively soft, and malleable, with low tensile strength. It is used in lead-acid storage batteries (see Cell, and Battery), solder, and plumbing, and as protective shielding against X-Rays and radiation from Nuclear Reactors (see Nuclear Energy). The principal lead ores are galena, cerussite, and anglesite. Lead Compounds (all poisonous) include tetraethyl lead (formerly used as a gasoline antiknock additive) and oxides (see Oxidation and Reduction) used in mordants and pigments. Continued exposure to lead-through inhalation of fumes or sprays and ingestion of food containing lead-can result in a cumulative chronic disease called lead poisoning. It was once a serious occupational hazard, but protective equipment and other precautionary measures have reduced its incidence. Lead poisoning remains a serious problem in children, who are more susceptible to it. Causes may include ingestion of paint chips from peeling walls or pipes (see Specifications - Piping) or inhalation of contaminated dust during home renovation. Lower doses may be treated by altering the diet to counteract lead's effects and and cleaning the person's environment to reduce intake. Higher doses are treated with chelating agents, drugs that remove lead from the body.