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Abstract: Geophagic soil samples from Swaziland were analyzed and characterized for their particle size, mineral content and geochemical composition. Texturally the samples were classified as silt loam except for two which were sandy loam. Minerals identified in the soils were dominantly quartz, and kaolinite, with plagioclase, microcline, muscovite, goethite and/or hematite, and illite-smectite. The SiO2 and Al2O3 concentrations were supportive of quartz and kaolinite dominance in the samples. Depletion and enrichment of trace and rare earth elements in the geophagic materials compared to average upper continental crust (UC), average Post-Archaean Australian Shale (PAAS) and average Swazi Granite (SG) were indicative of sediment geochemical characteristics. Values for chemical index of alteration (CIA) (78.30–99.75) and chemical index of weathering (CIW) (84.54–99.95) suggested low amounts of essential constituents in the geophagic soils. Dental enamel damage, abrasion of the gastro intestinal tract and rupturing of the colon of geophagic practitioners in Swaziland are possible health concerns related to ingestion of these soils. [Copyright &y& Elsevier]

This study compared the granulometric properties, mineralogical composition and concentrations of major and trace element oxides of commonly ingested soils (geophagic soil) collected from different countries with a view of understanding how varied they may be in these properties and to understand the possible health implications of ingesting them. Soil samples were collected from three different countries (South Africa, Swaziland and Democratic Republic of Congo (DRC)) and their granulometric properties, concentrations of major and trace element oxides as well as mineralogical composition determined. Differences were observed in the granulometric properties of geophagic soil from the three different countries with most of them having <20% clay content. The soils also showed varied degrees of weathering with values of Chemical Index of Alteration (CIA) and Chemical Index of Weathering (CIW) being between 60% and 99.9% respectively. The mineral assemblages of the soils from South Africa and Swaziland were dominated by the primary minerals quartz and feldspar whereas soils from DRC had more of kaolinite, a secondary mineral than primary minerals. Soils from DRC were associated with silt, clay, Al2O3, and CIA unlike most samples from South Africa which were associated with SiO2, sand, K2O, CaO, and MgO. The soils from Swaziland were closely associated with silt, H2O and Fe2O3(t). These associations reflect the mineralogy of the samples. These soils are not likely to serve as nutrient supplements because of the low concentrations of the nutrient elements contained. The coarse texture of the samples may also result in dental destruction during mastication. Sieving of the soils before ingestion to remove coarse particles is recommended to reduce the potential health threat associated with the ingestion of coarse-textured soils.