Value of the diagnostic sodium calcium edetate mobilization test as a criterion of lead absorption.

Among the laboratory tests available for the follow-up of lead-exposed workers, the EDTA mobilization test is presently underestimated in the diagnosis of lead intoxication. The authors present the results of regression comparison between the urinary lead excretion 3 h (PbU 3) or 6 h (PbU 6) after EDTA injection and blood lead (PbB), urinary aminolaevulinic acid (ALAU) and urinary lead (PbU). The results were collected from 133 medical examinations of workers exposed to lead, who put in a claim for compensation to the 'Fund of Occupational Diseases' in Belgium. On the basis of the regression curves, PbU 3 and PbU 6 limit values are calculated for different cut-off values of PbB in excessive lead absorption and lead intoxication. For each of these values the 'sensitivity', 'specificity' and 'validity' are calculated. As a result the authors still consider the EDTA mobilization test as a valuable parameter in the diagnosis of lead absorption.