Lead in the environment

Lead has been known and used since antiquity. Because of its ease of extraction, its malleability and low melting point, the ancient Romans used the metal and its compounds extensively - in pots and pans, in plates and cups, in paints and cosmetics and even in the building of aqueducts. 

The Romans also mined lead ores, mainly galena (PbS) and lead carbonate, for their silver content, the basis of coinage. After reducing the ore to a mixture of lead and silver, they passed air over the hot mixture, which oxidised the lead to PbO. While most of the PbO was absorbed into the bone-ash pot in which the reaction was done, around one per cent was lost to the atmosphere, and spread by air currents.