Using archaeometabolomics to characterise tobacco-usage in human cortical bone from 17th to 19th century Dutch communities

Detecting tobacco consumption in historical populations is a complex challenge often encountered by archaeologists. Traditional methods typically involve the morphological examination of teeth for pipe-notches and/or staining. However, when teeth are absent, discerning tobacco-usage becomes impossible, highlighting the need for alternative approaches. Recently, metabolomics has gained attention as a promising tool in the analysis of archaeological artefacts and human remains, offering new insights into ancient smoking habits. In this study, we applied a combination of reversed-phase (RP) C18 and hydrophilic interaction liquid chromatography (HILIC), both coupled with mass spectrometry, to analyse a Dutch population spanning pre- and post-tobacco archaeological contexts. Our statistical approach focused on the multivariate analysis of each assay, followed by the integration of the two datasets, and Random Forest modelling to test the effect of covariables. The results demonstrated some separation between tobacco consuming and non-consuming groups, as evidenced by distinct metabolomic profiles in the omic blocks. The single block model exhibited a bias towards correctly classifying the tobacco-consumer group, with a balanced estimation error of 0.375 for the C18 assay. Additionally, integrating the two datasets produced a similar classification accuracy potentially driven by the RP classification potential, particularly when distinguishing between pre- and post-tobacco contexts. Overall, our findings confirm the potential of mass spectrometry-based metabolomics as a powerful tool for studying tobacco consumption habits in past populations, although further work is needed to disentangle wider affects from other variables and tightly dated samples are needed. This method could be validated in the future and complement current morphological methods.