Department of Anthropology, University of Massachusetts Amherst, Amherst, MA 01003, UNITED STATES OF AMERICA.
Nearly 25 years ago federal officials unearthed over 400 skeletal remains in Lower Manhattan. The site of the excavation was the New York African Burial Ground (NYABG), a 17th- and 18th-century cemetery for the city’s mostly enslaved African population. Today, the burial ground serves as a reminder of New York’s 200-year experiment with slavery. It is the first National Monument to honor enslaved African New Yorkers. This recognition is a testament to the resolve of African American descendants and their allies who, through political activism, would see these ancestors afforded in death some of the respect denied them in life.
Descendant community activism also paved the way for the site’s interdisciplinary investigation, the NYABG Project. Recovering complex diasporic biohistories from the NYABG was a major scientific undertaking made more challenging and rewarding by the project’s high standards of public inclusion and accountability. Co-developed by community members and scholars, the NYABG Project now stands as a model of critically engaged biocultural anthropology.
This dissertation study draws upon and continues the work of NYABG researchers. It is a reconstruction of early life lead exposure via laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) of dental enamel. With its high inorganic content, enamel provides a stable chemical record of an individual’s diet, nutrition and pollution events, which in turn reflect political, economic and cultural factors. For this population, relatively high levels of skeletal lead suggest time spent in the Americas while low levels more likely indicate birth in Africa prior to forced migration. Here, lead concentrations in enamel that forms during the first several years of life are measured, mapped microspatially, and rendered as chronological age profiles. Mean differences and distribution/age profiles are compared for 44 NYABG children and adults in order to determine their African or American birthplaces and related health and cultural experiences (e.g., lead poisoning and dental modification). For some individuals, comparative analysis of later forming teeth was undertaken to explore the possibility of migration during childhood.
Enamel-lead concentrations range from 0.39 μg g-1 (i.e., the instrument limit of detection or LOD) to 14.7 μg g-1, suggesting a range of exposures in which some individuals spent their childhoods in high-lead environments. The most striking finding is that mean enamel-lead concentration for young children (5.88 μg g-1) is over five times that of adults (1.11 μg g-1), a significant difference reflecting these groups’ mostly American versus African geographic origins, respectively. Other findings raise questions at the intersections of natality, health and culture. For example, contra most reports, do relatively high lead concentrations for some individuals indicate that cultural dental modification persisted in the Americas?
This study is the first quantitative LA-ICP-MS analysis of human lead exposure in early America. LA-ICP-MS has proven critical for assessing overall lead burden as well as age-related changes in the sources and nature of exposure. The methodology developed for this study has enabled a rich assessment of African diasporic environmental biohistory, health and culture during slavery. As with the “rediscovery” of the NYABG, this is a moment and a tool for discovering new history and new dimensions of the human experience, then and now.