TITLE:
Arsenic Soil Concentrations in Mississippi River Floodplain Environments and the Influence of Sediment Acquisition and Dissimilatory Fe-Oxyhydroxide Dissolution on Arsenic Accumulation
AUTHORS:
Michael Aide
KEYWORDS:
Soil Arsenic, Sediment Source Fingerprinting, Mississippi River Alluvium, Arsenic Mitigation, Arsenic Fate and Transport
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.14 No.10,
October
27,
2026
ABSTRACT: The Mississippi River and its tributaries form a watershed that contains extensive farmland areas and industrial centers. The specter of metal and metalloid impact along the Mississippi River is a growing concern; however, selected areas along the Mississippi River have not been fully characterized for chemical impacts. In southeastern Missouri, two floodplain soil sites, each with two pedons were selected for geochemical analysis. Arsenic concentrations throughout the pedons were within the range for soils having no apparent arsenic accumulation. Na-acetate extractions indicate that most of the arsenic content is not highly bioavailable. Arsenic concentrations are significantly associated with Fe-oxyhydroxide abundance. Soils sampled from adjacent loess-covered uplands exhibit similar arsenic concentrations and are consistent with the likelihood that these uplands are a sediment source area. Additionally, enhanced Mississippi River sediment and erosional transport from loess uplands to the floodplains are understood to be a continuing process, thus environmental stewardship of these floodplain soils is advanced with knowledge of the sediment source areas. Arsenic research may ultimately become a valuable geochemical species for sediment source fingerprints.