Kaare Lund Rasmussen1, Lilian Skytte1, Paolo D'imporzano2, Per Orla Thomsen3, Morten Søvsø4, Jesper Lier Boldsen5. 1. Department of Physics, Chemistry and Pharmacy, University of Southern Denmark, Campusvej 55, DK-5230 Odense M, Denmark. 2. Faculteit der aard- en levenswetenschappen (cluster diepe aarde), Vrije Universiteit Amsterdam, Holland. 3. Arkaeologi Sydfyn, Anne Hvides Gård, Fruestraede 3, DK-5700 Svendborg, Denmark. 4. Sydvestjyske Museer, Tangevej 6, DK- 6760 Ribe, Denmark. 5. Department of Forensic Medicine, University of Southern Denmark, Lucernemarken 20, DK-5260 Odense S, Denmark.
Abstract
BACKGROUND: The differences in trace element concentrations among 19 different bone elements procured from 10 archaeologically derived human skeletons have been investigated. The 10 individuals are dated archaeologically and some by radiocarbon dating to the medieval and post-medieval period, an interval from ca. AD 1150 to ca. AD 1810. This study is relevant for two reasons. First, most archaeometric studies analyze only one bone sample from each individual; so to what degree are the bones in the human body equal in trace element chemistry? Second, differences in turnover time of the bone elements makes the cortical tissues record the trace element concentrations in equilibrium with the blood stream over a longer time earlier in life than the trabecular. Therefore, any differences in trace element concentrations between the bone elements can yield what can be termed a chemical life history of the individual, revealing changes in diet, provenance, or medication throughout life. METHODS: Thorough decontamination and strict exclusion of non-viable data has secured a dataset of high quality. The measurements were carried out using Inductively Coupled Plasma Mass Spectrometry (for Fe, Mn, Al, Ca, Mg, Na, Ba, Sr, Zn, Pb and As) and Cold Vapor Atomic Absorption Spectroscopy (for Hg) on ca. 20 mg samples. RESULTS: Twelve major and trace elements have been measured on 19 bone elements from 10 different individuals interred at five cemeteries widely distributed in medieval and renaissance Denmark. The ranges of the concentrations of elements were: Na (2240-5660 µg g-1 ), Mg (440-2490 µg g-1 ), Al (9-2030 µg g-1 ), Ca (22-36 wt. %), Mn (5-11450 µg g-1 ), Fe (32-41850 µg g-1 ), Zn (69-2610 µg g-1 ), As (0.4-120 µg g-1 ), Sr (101-815 µg g-1 ), Ba (8-880 µg g-1 ), Hg (7-78730 ng g-1 ), and Pb (0.8-426 µg g-1 ). CONCLUSIONS: It is found that excess As is mainly of diagenetic origin. The results support that Ba and Sr concentrations are effective provenance or dietary indicators. Migrating behavior or changes in diet have been observed in four individuals; non-migratory or non-changing diet in six out of the 10 individuals studied. From the two most mobile (most changing diet) individuals in the study, it is deduced that the fastest turnover is seen in the trabecular tissues of the long bones and the hands and the feet, and that these bone elements have higher turnover rates than centrally placed trabecular bone tissue, such as from the ilium or the spine. Comparing Sr and published bone turnover times, it is concluded that the differences seen in Sr concentrations are not caused by diagenesis, but by changes of diet or provenance. Finally, it is concluded that there can be two viable interpretations of the Pb concentrations, which can either be seen as an indicator for social class or a temporal development of increased Pb exposure over the centuries.
BACKGROUND: The differences in trace element concentrations among 19 different bone elements procured from 10 archaeologically derived human skeletons have been investigated. The 10 individuals are dated archaeologically and some by radiocarbon dating to the medieval and post-medieval period, an interval from ca. AD 1150 to ca. AD 1810. This study is relevant for two reasons. First, most archaeometric studies analyze only one bone sample from each individual; so to what degree are the bones in the human body equal in trace element chemistry? Second, differences in turnover time of the bone elements makes the cortical tissues record the trace element concentrations in equilibrium with the blood stream over a longer time earlier in life than the trabecular. Therefore, any differences in trace element concentrations between the bone elements can yield what can be termed a chemical life history of the individual, revealing changes in diet, provenance, or medication throughout life. METHODS: Thorough decontamination and strict exclusion of non-viable data has secured a dataset of high quality. The measurements were carried out using Inductively Coupled Plasma Mass Spectrometry (for Fe, Mn, Al, Ca, Mg, Na, Ba, Sr, Zn, Pb and As) and Cold Vapor Atomic Absorption Spectroscopy (for Hg) on ca. 20 mg samples. RESULTS: Twelve major and trace elements have been measured on 19 bone elements from 10 different individuals interred at five cemeteries widely distributed in medieval and renaissance Denmark. The ranges of the concentrations of elements were: Na (2240-5660 µg g-1 ), Mg (440-2490 µg g-1 ), Al (9-2030 µg g-1 ), Ca (22-36 wt. %), Mn (5-11450 µg g-1 ), Fe (32-41850 µg g-1 ), Zn (69-2610 µg g-1 ), As (0.4-120 µg g-1 ), Sr (101-815 µg g-1 ), Ba (8-880 µg g-1 ), Hg (7-78730 ng g-1 ), and Pb (0.8-426 µg g-1 ). CONCLUSIONS: It is found that excess As is mainly of diagenetic origin. The results support that Ba and Sr concentrations are effective provenance or dietary indicators. Migrating behavior or changes in diet have been observed in four individuals; non-migratory or non-changing diet in six out of the 10 individuals studied. From the two most mobile (most changing diet) individuals in the study, it is deduced that the fastest turnover is seen in the trabecular tissues of the long bones and the hands and the feet, and that these bone elements have higher turnover rates than centrally placed trabecular bone tissue, such as from the ilium or the spine. Comparing Sr and published bone turnover times, it is concluded that the differences seen in Sr concentrations are not caused by diagenesis, but by changes of diet or provenance. Finally, it is concluded that there can be two viable interpretations of the Pb concentrations, which can either be seen as an indicator for social class or a temporal development of increased Pb exposure over the centuries.
Authors: Rachel Simpson; David M L Cooper; Treena Swanston; Ian Coulthard; Tamara L Varney Journal: Archaeol Anthropol Sci Date: 2021-01-15 Impact factor: 1.989