Lead poisoning (plumbism) is defined simply as the undesirable health effects induced by that metal. Many of these, however, are “nonspecific”; that is, they are similar to or identical with symptoms and signs produced by causes other than lead, and some of the toxic effects are so subtle they require laboratory identification. This historical and geographic discussion concerns itself primarily with those overt effects obviously apparent upon even casual observation by nonmedical observers, which therefore are most likely to appear in the historical record. Principal among these are abdominal colic, muscle paralysis due to lead-damaged nerves, and convulsions.

Physiology

Lead gains access to the human body principally through the air we breathe and the substances we ingest. Residents of industrialized nations acquire about half of their “body burden” of lead from polluted respired air. Healthy adults only absorb about 10 percent of ingested lead, but children may absorb as much as half of the lead they eat or drink. Lead absorption is enhanced by a low level of calcium in the diet. Lead may also be absorbed through the skin. Prolonged applications of lead-containing substances such as poultices or cosmetics may result in health-threatening absorption of lead.

Absorbed lead is distributed throughout the body by the blood. The human body’s ability to excrete absorbed lead is so limited, however, that normal life activities in Western countries will produce lead absorption in excess of the body’s excretory capacity. About 5 percent of unexcretable lead is deposited in the liver, brain, and other viscera, where its residence time is only a matter of a few weeks.