The project "Investigating the Effects of the Industrial Revolution on Oral Biology & Health" developed from my suggestion to Professor Chris Gosden in 2013, to consider exploring ancient microbiomes. The resulting study of the dental calculus from the Radcliffe Infirmary excavation assemblage led to papers on metabolomics and on microbial differences between dental plaque and historic dental calculus. The current focus is on evaluating the significance of the microscopic analysis, by palaeobotanist Anita Radini, of the dental calculus in this study. Of particular interest is the plant material that has been identified. We are exploring the intriguing possibility that these findings might provide evidence of food adulteration with potentially injurious substances such as red lead. I have involved Janet Montgomery who carried out a pilot study of lead, and other metals, in dental calculus and enamel. I am sampling historic Cayenne pepper from the Wellcome Collection to facilitate our ongoing analysis.