HUMAN IN-VIVO MODEL FOR THE DETERMINATION OF LEAD BIOAVAILABILITY USING STABLE-ISOTOPE DILUTION

Beverages stored in lead-crystal glass accumulate extraordinary concen trations of lead. We obtained a lead-crystal decanter manufactured wit h lead from Australia, where the ratio of Pb-206/Pb-207 is distinctly different from that in the United States, We sought to determine the b ioavailability of crystal-derived lead, using the technique of stable isotope dilution in blood. We conducted a single-dose, nonrandomized c ross-over study in which participants were admitted to the Clinical Re search Center mice, 1 week apart. During the first admission, subjects ingested sherry obtained from the original bottle. During the second admission, they ingested sherry that had been stored in the crystal de canter and that had achieved a lead concentration of 14.2 mu mol/l. Af ter ingesting decanter-stored sherry, mean blood lead rose significant ly (p = 0.0003) from 0.10 to 0.18 mu mol/l, while mean Pb-206/Pb-207 f ell from 1.202 to 1.137 (p = 0.0001). On average, 70% of the ingested dose of lead was absorbed. We conclude that lead derived from crystal glass is highly bioavailable; repeated ingestions could cause elevated blood lead concentration. The technique of stable isotope dilution le nds itself to the study of the bioavailability of lead in other matric es, including soil.