Screening for lead poisoning with the urinary ALA test.

THE observation that elevated urinary concentrations of delta-aminolevulinic acid (ALA) are directly correlated with an excess body burden of lead in laboratory rabbits, industrial workers exposed to lead fumes (I), and children hospitalized with lead intoxication (2) suggested a simple, rapid, quantitative test for lead poisoning. The double ion-exchange column technique perfected by Davis and Andelman (3) made rapid determination of urinary ALA practicable. To assess the value of this technique as a screening method, demonstrate the feasibility of employing local teenagers in such a ghetto health project, and determine the prevalence of abnormal ingestion of lead in high-risk slum children, we organized a door-to-door canvass in the Bronx, N.Y., in July and August 1968. Although both the collection and the assay methods proved workable, the reliability of the ALA test was reduced by the variable dilution of the urine specimens.