ARCHAEOLOGICAL CHEMISTRY—EXPLORING HISTORY WITH CHEMISTRY - Chemistry: Notable Research and Discoveries - page 188

widespread Romans, several factors probably contributed to the weak-
ness that was eventually exposed by the “barbarians.” Archaeologi-
cal chemistry may be able to help decide which factors were the most
important.
One possibility involves the use of lead. Although heavy, this abun-
dant metal is easily worked—lead is soft, malleable, and has a low melt-
ing point. The Romans fashioned water pipes out of lead and used them
in many areas of their empire, especially Rome. So common was the use
of lead for this purpose that it influenced the English term plumbing,
which derives from the Latin word for lead, plumbum. (This Latin word
also explains the chemical symbol for lead, which is Pb.) Romans also
commonly boiled fruits such as grapes in lead vessels.
The use of lead in Roman and Greek civilizations was so great that it
caused widespread air pollution, which spread around the globe. Some of
this lead settled, along with snow, onto ice packs in Greenland, where it
lay on the surface until subsequent layers buried it. The snow turned to
ice as layers accumulated undisturbed over the millennia. At each depth
of the pack, the composition of the ice provides information on climate
and atmospheric composition at the time of the deposit. Researchers can
procure an ice core by drilling into the ice with a hollow bit, then chemi-
cally analyze the ice at various depths to study the atmosphere in ancient
times. In 1994, the geologists Sungmin Hong, Claude F. Boutron, and
their colleagues analyzed an ice core from Greenland that covered a pe-
riod from 3,000 to 500 years ago. As reported in “Greenland Ice Evidence
of Hemispheric Lead Pollution Two Millennia Ago by Greek and Roman
Civilizations,” published in Science, they found the concentration of lead
was four times higher than normal during the Roman era.
But lead is poisonous. Lead poisoning can cause elevated blood
pressure, pain, mental disorders, irritability, and infertility. The Ro-
mans were not completely unaware of the dangers of lead, for they
noted the poor health of the unfortunate men who produced and
worked with the metal. Yet this warning may not have been enough.
Perhaps the Romans believed that their exposure to lead leaching from
pipes or cooking vessels would not be serious.
Did the plentiful use of lead cause severe outbreaks of lead poison-
ing in the Romans? Archaeological chemists looking into this issue have
examined skeletons dating from Roman times. Lead accumulates in the
bones as the body absorbs this heavy element. The University of Minne-
sota researcher Arthur C. Aufderheide and his colleagues tested Roman