Assessing heavy metal exposure in Renaissance Europe using synchrotron microbeam techniques

Abstract

A number of archaeological studies have used chemical analysis of preserved, human biological tissues to assess the potential exposure of historic figures and ancient populations to heavy metals. Accurately assessing historic levels of heavy-metal body burden for these individuals based on analysis of remnant soft-tissue, hair and bone collected from preserved human remains is often complicated by the potential for post-mortem chemical modifications and contamination of the body and burial site. This study employs high-resolution, synchrotron-based elemental X-ray fluorescence mapping, tomography and absorption spectroscopy of human remains collected in an archaeological context in an effort to discriminate between heavy metals such as mercury and lead that may have been incorporated through either endogenous or exogenous processes. These methods were used to analyze bone and hair samples from Ferrante II of Aragon, King of Naples (1469–1496) and Isabella of Aragon, Duchess of Milan (1470–1524). These individuals are likely to have been exposed to generally similar levels of heavy metals in their lifetime, would have been embalmed using similar methods and the post-mortem exposure to contaminants is likely to have been similar. Although the remains from both Ferrante II of Aragon and Isabella of Aragon contain high amounts of mercury and lead, the high-resolution and –sensitivity synchrotron microprobe techniques employed in this study provide insight in to the likelihood these metals were incorporated pre-mortem rather than as ante-mortem contaminants. Although synchrotron X-ray fluorescence mapping and tomography are generally consistent with measured mercury from Isabella hair samples being endogenous in nature, the high levels of mercury seen in Ferrante II's remains are most likely related to post-mortem embalming of the corpse. However, application of microfocused X-ray fluorescence compositional mapping and lead L2 edge X-ray absorption spectroscopy to bone samples collected from Ferrante II show that the measured lead is likely endogenous and the result of in-life exposure to this heavy meta

Confocal x‐ray Fluorescence Imaging Facilitates High‐Resolution Elemental Mapping in Fragile Archaeological Bone

“…; Lanzirotti et al . ). The uptake of trace elements into bone microstructures through continuous remodelling during life makes bone a dynamic reservoir of trace elements.…”

Mercury in archeological hair samples from Xiongnu burials (Noin‐Ula, Mongolia): SR XRF and CXRM analysis

“…Then 10‐mg samples were taken and pressed into tablets (d = 6 mm) with a final mercury content of 10, 100, and 1,000 μg/g. Cellulose was chosen to be the matrix of artificial standard samples due to the closeness of its absorbing characteristics to those of hair …”

“…[9] However, in the literature, there are solutions to this problem: (a) inorganic mercury is most likely to come in exogenously, whereas organic mercury endogenously [15,16] ; (b) examination of the distribution of the chemical element across a cross section of a hair, as well as of the concentration gradient along its length, may indicate the nature of the element income. [17,18] When some additional sources of information of Hg content in the organism (such as bones and teeth) are presented in the archeological site, the lifetime and postmortem influences can be separated, using thoroughly analysis of all material, as was done in the work of S. Pessanha et al (2016), for example. [19] In our case, we have got 40 plates of hair belonging to different people.…”

“…No analysis of hair for total mercury content can separate the exogenous and endogenous influence . However, in the literature, there are solutions to this problem: (a) inorganic mercury is most likely to come in exogenously, whereas organic mercury endogenously; (b) examination of the distribution of the chemical element across a cross section of a hair, as well as of the concentration gradient along its length, may indicate the nature of the element income …”

“…It allows one to reduce the probing volume up to micrometers and nanometers . This method has allowed for investigation of different biological, geological, and archeological samples . However, the quantitative determination of elemental content remains a task to be solved in each separate case.…”