SKELETAL CONCENTRATIONS OF LEAD IN ANCIENT PERUVIANS

The level of biologic lead (expressed as the ratio of atomic lead to atomic calcium) in bones of Peruvians buried 1600 years ago was found to be 3 X 10-8, as compared to 2100 to 3500 X 10-8 in the bones of present-day residents of England and the United States. The ratio of barium to calcium was 2 to 3 X 10-6 in bones of ancient Peruvians and present-day Americans. Barium and lead have similar morphologic distributions in organisms, so this discrepancy for lead must result from overexposure of present-day people to industrial lead and not from natural variations. The magnitude of this discrepancy has been confirmed by two different lines of investigation not reported in this article. This new evidence suggests that natural interactions of lead in human cells have not yet been determined because reagents, nutrients and controls used in laboratory and field studies have been contaminated with lead far in excess of naturally occurring levels. (N Engl J Med 300:946–951, 1979) MAN has been exposed to anthropogenic lead for about 4500 years before the present (bp), when lead ores were first mined, smelted and cupeled in Southwest Asia to isolate traces of silver found in them.1,2 Since that time, human populations in the Old World have been exposed to industrial lead; therefore, their bones should not be used to measure natural lead levels. Bones of Peruvians buried in arid deserts were studied to compare, with minimum lead contamination from soil moisture, the effect of pre-copper smelting versus post-copper smelting and the effect of changes in diet from marine life to cereals. © 1979, Massachusetts Medical Society. All rights reserved.