Tracking natural and anthropogenic Pb exposure to its geological source

Abstract

Human Pb exposure comes from two sources: (i) natural uptake through ingestion of soils and typified by populations that predate mining activity and (ii) anthropogenic exposure caused by the exposure to Pb derived from ore deposits. Currently, the measured concentration of Pb within a sample is used to discriminate between these two exposure routes, with the upper limit for natural exposure in skeletal studies given as 0.5 or 0.7 mg/kg in enamel and 0.5/0.7 μg/dL in blood. This threshold approach to categorising Pb exposure does not distinguish between the geological origins of the exposure types. However, Pb isotopes potentially provide a more definitive means of discriminating between sources. Whereas Pb from soil displays a crustal average 238U/204Pb (μ) value of c 9.7, Pb from ore displays a much wider range of evolution pathways. These characteristics are transferred into tooth enamel, making it possible to characterize human Pb exposure in terms of the primary source of ingested Pb and to relate mining activity to geotectonic domains. We surmise that this ability to discriminate between silicate and sulphide Pb exposure will lead to a better understanding of the evolution of early human mining activity and development of exposure models through the Anthropocene.

Evaluation and Geostatistical Study of Toxicological Risk by Water Ingestion with Al, Ba, Fe and Pb in Communities Close to Industrial Areas in the Brazilian Amazon

“…Anthropogenic exposure to lead emerges predominantly as a result of interaction with Pb released into the environment through mining and use of sulfide deposits containing Pb. 54 Kuchler et al 48 found Pb concentrations around 0.0063 mg L -1 in the waters of the Negro River in Amazonas. Mining activities contribute to the increase in Pb levels in natural waters; the water used in the various steps of the beneficiation process and in the production of Al may contain high concentrations of trace metals.…”

A veritable confusion: use and abuse of isotope analysis in archaeology

“…Using isotope analysis to explore origins is an exclusive approach and equifinality remains a challenge, even when using multiple proxies. We are currently working to refine interpretation further by adding an additional proxy of lead isotope analysis (following Evans et al 2018b). Whist pinpointing precise locations will almost always be an impossibility, the evidence for diverse origins across Britain for the Wessex pigs is overwhelming and it is difficult to interpret the diversity of values across isotope proxies in any other way.…”

Multi-isotope analysis reveals that feasts in the Stonehenge environs and across Wessex drew people and animals from throughout Britain

“…The multi-isotope method can, however, refine provenance by discounting more potential source areas and by demonstrating the diversity of areas of origin. With improved mapping data and, potentially, the addition of other isotope proxies [e.g., Pb ( 33 )], the identification of origins may be possible in the future.…”