TITLE:
Southeastern Missouri Heavy Metal Soil Concentrations within Mississippi River Floodplain Environments
AUTHORS:
Michael Aide, Christine Aide
KEYWORDS:
Heavy Metals, Adsorption, Alluvium, Pollution Index, Lead
JOURNAL NAME:
Journal of Geoscience and Environment Protection,
Vol.13 No.7,
July
11,
2025
ABSTRACT: The Mississippi River watershed encompasses a substantial portion of the central United States, receiving effluent from soil runoff, urban and industrial centers. In Missouri, two soil series, with two pedons per series, located on the Mississippi River annual floodplain were morphologically described, classified, and chemically characterized. Aqua regia digestion and sodium acetate extractions were performed to assess the concentrations of 20 elements. A special emphasis was devoted to lead, cadmium, and zinc as these elements are commonly associated with heavy metal pollution. Cadmium was the only element showing an elevated concentration on one of the soil series. The pollution index and enrichment factor values suggested “cadmium impacted soils”. The elements used for geochemical background concentrations were determined using adjacent floodplain soils not experiencing annual Mississippi River flooding. However, geochemical background concentrations for cadmium were smaller than the sampled Mississippi River floodplain soils. Thus, the pollution index and the enrichment factor may have indicated “cadmium impacted soils”; however, the main difference is the soils used for the geochemical background soils and the Mississippi River floodplain soils simply exhibited slightly different cadmium concentrations. We conclude that cadmium may be accumulating in these annual flood prone soils; however, the intensity of the current cadmium accumulations is not appreciably above values that would warrant immediate remediation.