Background and History of Lead and its Uses

Lead is considered to be one the seven metals of antiquity. Its discovery has been trace to the development of processes for metal refining. The finding of the precious metal (silver) as an "impurity" in lead ore resulted in a surge in the mining of lead ore.

Archaeologists have found lead pigments on buildings constructed around 3,000 B.C. The color is still easy to identify after the passage of 5000 years. This quality of lead pigments helps explain why it has been used as an additive in paint for centuries. High-lead paint was equivalent to high-quality paint. However, even in the 19th century when more harmful health effects were observed to be caused by the manufacture and use of lead, increasing quantities of lead were being mined, smelted, and used as pigments in paint as well as other uses.

That trend was reversed earlier in other countries. France, for example, in 1840 instituted a policy which discouraged the use of lead as a pigment in paint. Zinc oxide was used to replace white lead as the white pigment. In 1870 Germany banned the manufacture of lead paint pigments after concluding that it was too dangerous to manufacture. Titanium dioxide and zinc oxide were substituted for the lead pigments. In 1904, on the other side of the world, lead was banned as a pigment for paint in Queensland, Australia. In spite of the early evidence and the restrictions in other countries, the United States and the United Kingdom continued to allow the use of lead in paint.

Lead has numerous properties which have found great favor with plumbers for centuries. Among these are that:

·        it is durable and very workable,

·        does not corrode,

·        expands when water freezes (thus preventing a pipe from bursting),

·        it does not readily crack due to building settling etc.,

·        does not readily burst with freezing and thawing.

·        When it does burst, the fractures could usually be temporarily repaired by mashing the leaking area.