Age and sensitivity to lead toxicity: a review.

During the past 20 years considerable attention has been focused on the epidemiologic features of childhood lead poisoning in the United States. Large numbers of children with symptomatic intoxication, as well as those with incipient symptoms, were commonplace a decade ago for physicians working in inner-city hospitals. With the recent availability of improved screening techniques, as well as a variety of environmental control measures, the incidence of symptomatic lead poisoning in children has diminished significantly in recent years. With the focus shifting from children with dangerously elevated body lead burdens to those with less significant exposures, increased attention has been directed to the various inherent metabolic and physical characteristics of the young that may influence the toxic effects of lead exposure. A number of differences with respect to lead exposure, absorption and retention, and varying nutritional conditions between children and older individuals are discussed. Experimental studies dealing with age differences of lead-treated animals are examined, and relevant human studies are reviewed.