Lead speciation, bioaccessibility and source attribution in Missouri's Big River watershed

Applied Geochemistry
By: , and 

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Abstract

The Southeast Missouri Lead District is among the most productive lead deposits exploited in modern times. Intensive mining conducted prior to regulations resulted in a legacy of lead contaminated soil, large piles of mine tailings and elevated childhood blood lead levels. This study seeks to identify the source of the lead contamination in the Big River and inform risk to the public. Isotopic analysis indicated the mine tailing piles at the head of the Big River are the primary source of the lead contamination. The isotopic signature of the lead in these mine tailings matched the lead over 100 km downstream. All of the other potential lead sources investigated had different isotopic signatures. Lead concentrations in soils and sediments decrease with distance downstream of the mine tailings piles. Additionally, the speciation of the lead changes from predominantly mineralized forms, such as galena, to adsorbed lead. This is reflected in the in-vitro bioaccessibility assay (IVBA) analysis which shows higher bioaccessibility further downstream, demonstrating the importance of speciation in risk evaluation.

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Publication type Article
Publication Subtype Journal Article
Title Lead speciation, bioaccessibility and source attribution in Missouri's Big River watershed
Series title Applied Geochemistry
DOI 10.1016/j.apgeochem.2020.104757
Volume 123
Year Published 2020
Language English
Publisher Elsevier
Contributing office(s) Geology, Geophysics, and Geochemistry Science Center
Description 104757, 11 p.
Country United States
State Missouri
Other Geospatial Big River watershed
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