Solubilization of lead from crystal dust in protein solution (pseudointerstitial fluid) and gastric juice

Since several workers engaged in polishing and engraving crystal articles were found to have higher than average blood levels of lead (560 μg/liter, range 80-560 μg/liter), we investigated the hypothesis that crystal dust releases lead in the human body. To test the hypothesis, two types of crystal polishing dusts, having different lead contents, were mixed with human serum diluted 1:3 (pseudointerstitial fluid), gastric juice, and phosphate buffer at pH 9. After 14 days of contact, the diluted serum had extracted 0.620% of the lead in the crystal dust (particle size <20 μm) containing 25.2% lead and 0.425% of that containing 19.9% lead. After 48 hr in gastric juice, 0.235 and 0.556% of the lead was extracted from crystal dusts (unsieved crystal dusts) containing 25.2 and 19.9% lead, respectively. After 28 days in alkaline solution, 0.358 and 0.304% of the lead was extracted respectively from the same two crystal dusts (unsieved crystal dusts).