Quantitative determinations and imaging in different structures of buried human bones from the XVIII-XIXth centuries by energy dispersive X-ray fluorescence – Postmortem evaluation

Abstract

In this work, a non-commercial triaxial geometry energy dispersive X-ray Fluorescence (EDXRF) setup and a benchtop µ-XRF system were used to identify postmortem contamination in buried bones. For two of the individuals, unusually high concentrations of Cu and Pb, but also Zn (in one individual) were observed. The pigments of the burial shroud coverings have been identified as the source of contamination. Accurate and precise quantitative results were obtained by nondestructive process using fundamental parameters method taking into account the matrix absorption effects. A total of 30 bones from 13 individuals, buried between the mid-XVIIIth to early XIXth centuries, were analyzed to study the elemental composition and elemental distribution. The bones were collected from a church in Almada (Portugal), called Ermida do Espírito Santo, located near the Tagus River and at the sea neighbourhood. The triaxial geometry setup was used to quantify Ca, Fe, Cu, Zn, Br, Sr and Pb of powder pressed bone pellets (n=9 for each bone). Cluster analysis was performed considering the elemental concentrations for the different bones. There was a clear association between some bones regarding Fe, Cu, Zn, Br and Pb content but not a categorization between cortical and trabecular bones. The elemental distribution of Cu, Zn and Pb were assessed by the benchtop μ-analysis, the M4 Tornado, based on a polycapillary system which provides multi-elemental 2D maps. The results showed that contamination was mostly on the surface of the bone confirming that it was related to the burial shroud covering the individuals.

Trace element distribution in human cortical bone microstructure: the potential for unravelling diet and social status in archaeological bones

“…These findings prompted Lambert et al [47] to suggest that researchers remove a bone's outer surface before taking a sample for analysis. With regard to a shallow contamination of cortical bone by a number of elements, the findings of Lambert et al [47,48] were duplicated and refined by more recent studies [1,2,49,50]. Furthermore, rather large differences in the trace-element chemistry of different bones have been observed, even within single individuals [8,29,51,52].…”

Mapping diagenesis in archaeological human bones

“…That requires high-resolution analyses of bone microstructure. The chemical composition of cross-sections of long-buried bones has previously been examined with scanning electron microscopy energy dispersive X-ray (SEM-EDX), X-ray fluorescence (XRF), proton induced X-ray emission (PIXE), synchrotron radiation (SR), and atomic absorption spectroscopy (AAS) [36][37][38][39][40][41]. The instrumentation used in the present study yields images with high resolution and good detection limits, hence a good approximation of precisely where specific elements are concentrated.…”

Um possível caso de sífilis adquirida num esqueleto oriundo da Ermida do Espírito Santo (séculos XV–XIX, Almada, Portugal)

“…Alguns trabalhos anteriores realizados nesta população esquelética descrevem casos de politraumatismo, mortalidade materna e neonatal, práticas funerárias e uso medicinal de mercúrio (Curate et al, 2013;Curate et al, 2015;Guimarães et al, 2016;Pessanha et al, 2016).…”

“…O indivíduo foi observado macroscopicamente -com o auxílio de uma lupa de magnificação -tendo sido ainda realizada uma análise ao conteúdo de mercúrio no crânio através de espectrometria de fluorescência de raios-X (Guimarães et al, 2016). A sua estatura foi estimada em 158,2 cm (comprimento máximo do fémur: ±5,96 cm [Mendonça, 2000]).…”

“…A epígrafe jocosa citada por Waldron (2008: 102) é reveladora da associação popular da sífilis venérea ao mercúrio: «Uma noite com Vénus e uma vida inteira com Mercúrio». A elevada concentração de mercúrio no cabelo de uma mulher adulta com graves lesões dos membros inferiores (Curate et al, 2013), mas sem qualquer tipo de lesão relacionada com treponematoses, também sepultada na Ermida do Espírito Santo, foi atribuída à aplicação médica de um composto de mercúrio, provavelmente para tratar uma infestação de piolhos (Guimarães et al, 2016). O mercúrio era também utilizado na Idade Média para desinfetar feridas (Maillard et al, 2007), uso consentâneo com as graves lesões observadas em ambas as pernas deste indivíduo.…”