%Lead

Lead (Pb) occurs mainly in the divalent form, Pb²⁺, although tetravalent Pb⁴⁺ may be found in very oxic environments. Natural Lead compounds are inorganic and there are little known methylation of Lead in the environment. Lead minerals have low solubilities in water, dissolution increasing to some extent in acid conditions; Lead phosphates, especially pyromorphite, are particularly insoluble. Lead is used in the electrodes, which are alternating plates of metallic Lead and Lead dioxide paste immersed in H₂SO₄. The historical extraction of Lead from the Earth's crust and its production, use and disposal, have significantly contaminated soils and water bodies. Lead is emitted to the atmosphere from Lead ore processing and smelting, areas of open mine waste, Lead-acid battery factories, fossil fuel combustion and waste incineration, especially where rigid PVC products are burned. The children suffered encephalopathy after exposure to Lead-contaminated soil and dust caused by informal dismantling of lead-acid batteries.