Assessment of lead stores in children: Validation of an 8-hour CaNa₂EDTA provocative test

Twenty-four-hour CaNa₂EDTA provocative tests for the assessment of lead stores were successfully performed in 36 asymptomatic children with mild to moderate undue lead absorption (blood lead concentration ≤69 μg/dl and erythrocyte protoporphyrin ≥50 μg/dl). By comparing lead excretion during the first 8 hours with that excreted during the entire 24-hour test, new criteria have been developed to define positive outcomes. We suggest that the excretion of ≥200 μg lead per 8 hours or a ratio of urinary lead (μg)/CaNa₂EDTA administered (mg)≥0.70 after a single intramuscular injection of CaNa₂EDTA (500 mg/m²) can identify those children who will respond to chelation treatment with lead diuresis.