"ULtra-clean" isotope diultion/mass spectrometic analyses for lead in human blood plasma indicated that most reported values are artificially high.

Abstract

We measured lead concentrations in venous blood plasma from two subjects, one having a typical exposure and the other a high exposure to lead. Our preliminary data, obtained by isotope dilution/mass spectrometric techniques in an ultra-clean laboratory, show lead concentrations of 0.02 mug/L and 2 mug/L, respectively, in their blood plasma, and 110 mug/L and 800 mug/L, respectively, in samples of whole blood. These results indicate that plasma lead concentrations previously reported have been overestimated by a large factor, and that further improvements in analytical procedures are needed in most laboratories before data on lead concentratios in blood plasma can be properly interpreted. Our preliminary data indicate a positive correlation between lead intake and lead concentrations in blood plasma.