The lead content of blood serum

Serum lead concentrations measured by stable isotope dilution with a therma l ionization mass spectrometer and blood lead concentrations measured by gr aphite furnace atomic absorption spectrophotometry are reported for 73 wome n of child bearing age resident in Los Angeles, California, The two quantit ies are related by the line y = 0.00030 + 0.00241x (r = 0.83), where y is s erum lead concentration and x is blood lead concentration, both being expre ssed in units of mug/L. The linearity of the relationship appears to hold t o a blood lead concentration of at least 60 mu gPb/L. The slope of the line indicates that lead in serum is 0.24% of that in whole blood in contrast t o recent reports of between 0.32 and 0.35% determined by inductively couple d plasma (ICP) mass spectrometry with bismuth used as an internal standard. The discrepancy stems from the ICP mass spectrometer-generated curves not passing through the origin. (C) 2001 Academic Press.