Flameless atomic absorption spectroscopy was used to measure lead concentrations in samples from 5 selected human skeletal sites (tibia, skull, rib, ilium, and vertebra) obtained from 134 hospital autopsies. Lead was distributed unequally among the different bones in distinct patterns that were age-, and to some extent, sex-dependent. To estimate lead concentration of the entire skeleton, all skeletal bones were divided into 5 groups based on their approximate compact/trabecular bone ratios, considering each of our 5 sampled sites to be the prototype for each such group. Regression analysis of the 10 possible bone site pair values at different ages yielded age-related constants. These constants were incorporated into an equation we developed that can be used both to estimate mean skeletal lead concentration (Pb) of the entire body skeleton and also to predict the lead concentration at any of the other 4 bone sites if any 1 of the 5 is measured. Applications of these data to in vivo bone lead measurements are detailed with respect to selection of the site to be measured, estimation of total skeletal lead burden, anticipated variations or error, and dependence of these factors on age and sex of the sampled population.

A method for direct lead content analysis of milligram quantities of bone ash by flameless atomic absorption spectroscopy is described. Bone ash (25 mg) is dissolved with HNO3 and diluted with H2O and La2O3 (1,000 micrograms/ml) solution. Lanthanum ion is used to suppress matrix interferences possibly arising in part from sulfate components of the bone ash. Two bulk bone samples (about 14 and 60 micrograms Pb/g ash, respectively) were used to determine daily, within-day, and overall variability of the method. Values for "low lead" bone samples were 14.08 +/- 1.74 (SD) microgram Pb/g ash and for "high lead" bone samples were 60.85 +/- 5.24 (SD) microgram Pb/b ash. The overall value of 58 lead recovery determinations from bone ash analysis was 103.5% (+/- 12.9% SD). These values compare favorably with results previously reported using gram amounts of sample.

We developed a chemical method to quantitate lead in small skeletal specimens and used it to establish lead distribution and quantitation in modern skeletons for all age groups to standardize sampling sites. Application of the method to excavated ancient skeletal collections enabled prediction of socioeconomic status among Colonial Americans, as well as identification of lead poisoning in ancient Rome as related to lead production and in an 18th century Caribbean epidemic as related to distillation of rum. Depending upon the conditions of burial, bones may be contaminated by surrounding material. This can be a limiting factor for interpretation of lead levels, but multielement analysis and procedural modifications can permit continuing application of bone lead analysis to appropriately selected archaeological skeletal collections.

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