Toxicology of lead: primer for analytical chemists

Through the years, considerable amounts of Pb have been mobilized into our environment, and Pb may represent one of the most ubiquitous of all toxic metal contaminants. Excluding occupational exposure, the general population receives almost 70% of its total exposure to Pb from food. Other important sources of exposure include drinking water and air; minor sources include tobacco products, decorative glassware, and other types of food utensils. For young children, ingestion of Pb-containing soil or dust via normal hand-to-mouth activity or, in extreme cases, pica (the abnormal intake of soil, paint chips, etc.) may represent a significant source of exposure. The severity of clinical manifestations of Pb toxicity depends on both duration and intensity of exposure. Infants and young children are more susceptible to the effects of Pb than are adults. Although there is little debate over the serious consequences of acute, high-level Pb exposure, both controversy and concern have been expressed about the degree of risk that may be associated with chronic exposure to Pb levels that are closer to contemporary levels in the general environment. This concern is particularly high with regard to infants and young children, who may undergo Pb-induced changes that have long-term neurological impact (e.g., learning deficits, gross and/or fine motor dysfunction, impaired cognitive abilities).