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Excavating human skeletons is the closest archaeologists can get to the people who lived in the past. Once excavated the bones are often analysed chemically in order to yield as much information as possible. Most archaeometric analyses performed on samples of human skeletal remains have been performed on a single sample from a tooth or a long bone. In this paper we investigate how a suite of elements (Mg, Al, Ca, Mn, Fe, Zn, As, Sr, Ba, Hg and Pb) are distributed in two medieval skeletons excavated at the laymen cemetery at the Franciscan Friary in Svendborg, Denmark. The analyses have been performed using CV-AAS for Hg and ICP-MS for the rest of the elements. We find that in general Hg concentrations are highest in the trabecular tissues and in the abdomen region. Our data also show that the elements Al, Fe and Mn concentrate in the trabecular tissue and on the surfaces of the bones. The two individuals can be clearly distinguished by Principal Component Analysis of all the measured trace elements. Our data support a previously published hypothesis that the elemental ratios Sr/Ca, Ba/Ca and Mg/Ca are indicative of provenance. Aluminium, Fe and Mn can be attributed to various forms of diagenesis, while Hg is not present in sufficiently large amounts in the surrounding soil to allow diagenesis to explain the high Hg values in the trabecular tissue. Instead we propose that Hg must originate from decomposed soft tissue.

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.

We describe a procedure for ascertaining the extent of diagenesis in archaeological human skeletons through the distribution of Sr, Ba, Cu, Pb, Fe, and Mn in cross-sections of femoral cortical bone. Element mapping is performed through Laser Ablation Inductively Coupled Plasma Mass Spectrometry (LA-ICP-MS). Absolute calibrations of element concentrations were obtained using Inductively Coupled Plasma Mass Spectrometry (ICP-MS) on adjacent dissolved bulk bone samples. By comparing a modern individual to five medieval to early modern Danish skeletons, we demonstrate the degree to which concentrations of trace elements are attributable to diagenesis. Invasion from the exterior bone surface into a degraded part of the outer cortical bone is the most frequently occurring diagenetic change. In the archaeological skeletons investigated, diagenetic modification is restricted to, at most, the outer ca. 0.5 mm of bone. In one femur, Haversian channels were filled with diagenetic material, which appears to have entered the bone through a network of cavities largely made up by Haversian and Volkmann's canals.

The differences in trace element concentrations can be interpreted as indications of varying diet and provenance as a function of time in the life of the individual - a concept which can be termed chemical life history. A few examples of the results of such analyses are shown, which contains information about provenance and diagenesis.

Background:The Franciscan Friary in Montella near Avellino in Southern Italy is of special interest because according to historical sources it was founded by St. Francis himself in AD 1221-1222. Human remains of several hundred individuals interred in the cloister walk have been unearthed during two excavation campaigns conducted in 2007-2008 and 2010. The environs of the friary have remained rural since the foundation preventing much modern contamination. The state of preservation of the skeletons is fair to good making a suite of analyses worthwhile. Results:The skeletons have been examined anthropologically and tissue samples have been subjected to radiocarbon dating, stable isotope measurements and trace element analyses by Inductively Coupled Plasma Mass Spectrometry and Cold Vapour Atomic Absorption Spectrometry. Conclusions:The radiocarbon dates are consistent with the historical sources and show that the cemetery in the cloister walk has been in uninterrupted use from the foundation of the friary in AD 1221-1222 and until the cemetery went out of use in AD 1524. The anthropological investigations show that the individuals interred at the friary would have been shorter than other Italians from the same time, and it seems that tuberculosis was more prevalent than leprosy. Isotopic measurements show a mixed agricultural and pastoral diet and none of the individuals were consuming marine protein. Based on the trace element analysis it seems that the people resided mainly at two distinct geographical areas, one of which was Montella. One individual stands out from the rest, because he was born and raised at some third geographical location distinct from Montella and because he sports the second oldest radiocarbon date of AD 1050-1249 (two sigma calibrated range). This date is consistent with the first generation of the founders of the friary-perhaps one of St. Francis' fellow travellers from Assisi.

Toxicological interaction represents a challenge to toxicology, particularly for novel contaminants. There are no data whether silver nanoparticles (AgNPs), present in a wide variety of products, can interact and modulate the toxicity of ubiquitous contaminants, such as nonessential metals. In the current study, we investigated the toxicological interactions of AgNP (size=1-2nm; zeta potential=-23mV), cadmium and mercury in human hepatoma HepG2 cells. The results indicated that the co-exposures led to toxicological interactions, with AgNP+Cd being more toxic than AgNP+Hg. Early (2-4h) increases of ROS (DCF assay) and mitochondrial O levels (Mitosox® assay) were observed in the cells co-exposed to AgNP+Cd/Hg, in comparison to control and individual contaminants, but the effect was partially reverted in AgNP+Hg at the end of 24h-exposure. In addition, decreases of mitochondrial metabolism (MTT), cell viability (neutral red uptake assay), cell proliferation (crystal violet assay) and ABC-transporters activity (rhodamine accumulation assay) were also more pronounced in the co-exposure groups. Foremost, co-exposure to AgNP and metals potentiated cell death (mainly by necrosis) and Hg (but not Cd) intracellular levels (ICP-MS). Therefore, toxicological interactions seem to increase the toxicity of AgNP, cadmium and mercury.