Applying trace element geochemistry of archaeological bone to study the coevolution of environmental change and human health in the Roman Empire.

Technological change has affected human health dating back to at least the Neolithic agricultural revolution. Growing evidence indicates widespread environmental pollution began with metallurgical practices and continues today. Environmental exposures to trace elements released from these practices have the potential to alter human body composition, such as bone mineral chemistry, especially for elements that are not homeostatically regulated. These signals can be used for inferences about human health, particularly when metallotoxins are detected in abundance. Therefore, trace element geochemistry of archaeological bone may provide a means to evaluate human health through time. However, diagenetic factors can hinder attempts to extract this information. Thus, we employed advanced analytical and interpretive methods to carefully distinct groups of European burials over about 1000 years to address questions of potentially toxic trace element exposures. Here, to address our hypothesis that Roman urbanization created one of the earliest urban toxic environment caused by multiple exposures, we present a comprehensive suite of bone trace element compositions of femora from burials spanning three distinct archaeological time periods (Bronze Age, Iron Age, and Roman period). All bone specimens were obtained from the anterior-mid shaft of carefully selected femora and processed using the same analytical techniques designed to mitigate soil contamination. Our data indicate that widespread environmental pollution accelerated in Londinium during the Roman Empire period, leading to conditions where population health would be vulnerable to environmental changes. Specifically, bone lead, silver, vanadium, arsenic, and cadmium concentrations were typically elevated and would likely be associated with multiple toxicities. In addition, bone iron levels were extremely high in some Londinium burials. Our interpretation is that the Romans inhabiting Londinium were not just poisoned by lead exposure as several previous studies show but by several metallotoxins.

The Influence of Environmental Exposure to Heavy Metals on the Occurrence of Selected Elements in the Maxillary Bone.

The elemental composition of the body's calcified tissues may reflect the environmental exposure of the population to heavy metals. The aim of the study was to assess whether the elemental composition of the maxillary bone from individuals belonging to a given population reflects the environmental exposure of this population to lead and cadmium. The research material consisted of cortical bone from the anterolateral walls of the maxilla collected from 126 patients during Caldwell-Luc maxillary sinus surgery on residents of two cities differing in terms of the lead and cadmium pollution of the natural environment. The content levels of lead, cadmium, iron, manganese, chromium, copper, and iron were determined by using atomic absorption spectrophotometry. The content levels of lead and cadmium in the samples of the maxillary bones of residents of Bielsko-Biala were 3.26 ± 2.42 µg/g and 0.74 ± 0.38 µg/g, respectively, whereas in the samples from the residents of Katowice, they were 7.66 ± 2.79 µg/g and 1.12 ± 0.08 µg/g, respectively. It was found that the lead and cadmium levels in the maxillary bone corresponded to the environmental exposure to these heavy metals in the place of residence, which was proven here via the example of the residents of two cities with different concentrations of these heavy metals in the air over long time periods. Additionally, higher content levels of essential metals such as manganese, chromium, copper, and iron are characteristic of the maxillary bone samples of residents of the area that is more polluted with heavy metals.

Raman Microscopy and Bone.

Raman microscopy is a nondestructive technique requiring minimal sample preparation that can be used to measure the chemical properties of the mineral and collagen parts of bone simultaneously. Modern Raman instruments contain the necessary components and software to acquire the standard information required in most bone studies. The spatial resolution of the technique is about a micron. As it is nondestructive and small samples can be used, it forms a useful part of a bone characterization toolbox.

The current state and future directions of skeletal toxicology: Forensic and humanitarian implications of a proposed model for the in vivo incorporation of drugs into the human skeleton.

At present, the inability to meaningfully and reliably conduct toxicological testing on human skeletal material represents a significant gap in forensic practice, especially in a time when the U.S. has declared opioid use a public health emergency and chemical weapon use in both mass and isolated attacks is prevalent in international news. In recent years, an increasing number of case studies and experiments have been published in an attempt to fill this knowledge gap. These papers are reviewed, and their valuable and pertinent findings discussed. However, the lack of an established model for the incorporation of drugs of forensic interest into bone has limited interpretation of results and delayed adoption of skeletal toxicology methods into accepted forensic practice. A model for the in vivo incorporation of drugs of forensic interest into bone tissue is proposed herein. This model is derived from known pathways for in vivo incorporation of compounds and analytes not of traditional forensic interest into bone tissue and is based on principles of ionic exchange, adsorption, and substitution. Testing and understanding these pathways may better guide skeletal toxicological experimentation, resulting in methods more tailored to human bone as a unique, largely inorganic matrix, as well as in increased interpretability of results. Further, the proposed model suggests possible novel applications for the field of skeletal toxicology on the humanitarian stage. Indeed, based on their chemical properties, chemical weapon nerve agents should be investigated as xenobiotics that may incorporate into the human skeleton at relatively elevated levels. If nerve agents can be isolated from skeletal remains, the field of skeletal toxicology may be able to offer important contributions to human rights investigations of mass graves.

Practical Considerations in Trace Element Analysis of Bone by Portable X-ray Fluorescence.

Forensic anthropologists are more often turning to nondestructive methods to assist with skeletal analyses, specifically for trace elemental analyses. Portable XRF (pXRF) instruments are versatile and are able to be used in diverse settings or for specimens of a shape and size that cannot be accommodated by laboratory-based instruments. Use of XRF requires knowledge of analysis parameters such as X-ray penetration and exit depth. Analysis depth was determined by examining pure elements through known thicknesses of equine bone slices. Correlation between the element's X-ray emission energy and the depth of reading was observed. Bone surfaces from a small unknown historic cemetery were analyzed before and after sanding of the periosteal surface to observe possible changes in XRF readings based on potential diagenesis. Results validate the pXRF device as a powerful and convenient instrument for nondestructive analysis, while highlighting limitations and considerations for the analysis of osseous materials.