Clinical and sub-clinical lead poisoning: a laboratory perspective.

1. The background, scope and limitations of laboratory methods for the diagnosis of inorganic lead poisoning are outlined in the context of the work of a specialist clinical laboratory for trace element analysis. 2. Data for blood lead, haemoglobin and erythrocyte zinc protoporphyrin concentrations are presented in cases of clinical and sub-clinical poisoning due to accidental or occupational exposure. 3. Data from population surveys of children and adults subject to either environmental or occupational exposure are also shown. 4. In general, analysis for lead in an appropriate specimen of blood offers the single most useful index of exposure. 5. The importance of good accuracy control in such measurements is emphasized.