Lead
Authors: Jacobs David E. 
Published: January 2012

Lead is an important industrial commodity that has numerous adverse health effects, even at relatively low levels of exposure. Historically, it has had more uses than any other metal. The mining of lead‐containing ores began in antiquity as mentioned in the Old Testament (Hebrew Bible). Nikander, a poet in the second centurybc, wrote the first recorded description of lead poisoning, explicitly recognizing the association between lead exposure and colic, paralysis, visual disturbances, peripheral neuropathy, and encephalopathy:

The harmful cerussa (lead carbonate), that most noxious thing,

Which foams like the milk in the earliest spring,

With rough force it falls and the pail beneath fills,

This fluid astringes and causes grave ills …

He soon cannot swallow, foam runs from his lips,

He belches so much, and his belly does swell,

His sluggish eyes sway, then he totters to bed,

Complains that so dizzy and heavy his head,

Meanwhile there comes a stuperous chill,

His feeble limbs droop and all motion is still,

His strength is now spent and unless one soon aids,

The sick man descends to the Stygian shades.Cited in Needleman, HL, Human Lead Exposure, CRC Press, 1992, p. 157.

Lead was used in ancient Egypt in coins, weights, ornaments, cosmetics, utensils, ceramic glazes, and solder. The Romans also found many uses for lead, including conduits for drinking water, which probably contributed to excessive lead exposure for the general population. Although descriptions of the toxic effects of lead appeared very early in history, the association between the use of lead in industry and health effects was very slow to evolve. The descriptions provided by the early observations of physicians such as Tanquerel des Planches and Thomas Oliver are milestones in the recognition of the multiorgan effects of lead. Insights into mechanisms did not appear until the twentieth century in parallel with the broader understanding of human biology and the emergence of the practice of medicine as a science. For example, the review by Aub provides early insights into mechanisms of lead toxicity, particularly the role of bone in lead metabolism. Over the next decades, the correlation between pathological and clinical effects of lead on organ systems was better defined, as was the significance of specific ranges of blood lead levels and routes of exposure in both the workplace and the community with the advent of modern industrial hygiene. A concise overview of the status of the toxicology of lead for some 30 years is contained in Ethyl Browning's monograph on the toxicity of industrial metals. There continues to be an extensive and expanding body of new scientific literature on the effects of lead at the systemic, cellular, and molecular levels. This allows for more precise interpretation of relationships between exposure and effect, reviewed most recently and extensively in 2007 by the Agency for Toxic Substances and Disease Registry (ATSDR). These few historic references provide perspective and appreciation for the evolution of present‐day concerns and workplace and community practices regarding lead.

The objective of this chapter is to integrate the emerging scientific advances in the toxicology of lead with the occurrence and recognition of both clinical and subclinical effects. A list of current publications regarding health criteria and protective regulatory and guidance measures for exposure to lead in the community (with a focus on children) and workplace are also provided.