Lead burden in prehistorical, historical and modern human bones.

From archaeological findings it is well known that, in the past, lead has been intensively used by man. The toxicological aspects of increased lead exposure are perceived onward from the 2nd century B.C.; between 90 and 95% of the absorbed lead is stored in bone. Therefore measurement of lead levels in ancient bones seemed to be a suitable approach to determine the real body burdens at different periods of time and to compare the results with the present situation. Approximately 650 bones from a total of 332 individuals of the following epochs were analysed: prehistorical Peruvians, prehistorical Teutons, late Romans, Middle Age (further differentiated), present time Germans. The determination of lead was made by graphite furnace atomic absorption spectroscopy. The possibilities of postmortem alterations of lead concentrations were thoroughly investigated. For this purpose the dependence of the lead concentrations found were compared with the age, sex, type of bone, conditions of preservation and storage. It is concluded that only the series "prehistorical Teutons" may be exposed to levels which are relevant to postmortem changes. The lead concentration of the group "prehistorical Peruvians" can be taken as the "physiological zero point"; from this culture no use of lead is known. The present body burden for lead in germany is about 20 times greater than this "physiological zero point". In the late Roman epoch, but also in the Middle Age the lead concentrations and body burden was 41-47% of that today. Only at the time after the Barbarian Invasions did this value drop to 13% as a result of a lower living standard. The different sources of lead exposure during Roman times, the Middle Age and today are discussed.