Geochemical and mineralogical composition of geophagic materials from Baringo town, Kenyan Rift Valley and their possible health effects on the consumers.
Level 5 - mechanism / opinion, no new human data
Level 5 by design analogy; laboratory bench analysis of physical samples without human clinical data.
PubMed 34041654 · doi:10.1007/s10653-021-00960-9
What was done
Twelve representative samples of geophagic rock materials were purchased from an open market in Baringo town, Kenya. Mineralogy and crystal morphology were analyzed using optical microscopy, scanning electron microscopy, and X-ray diffractometry. Major and trace element concentrations were measured using X-ray fluorescence and inductively coupled plasma mass spectrometry to evaluate potential health risks.
What was found
Samples contained 10% to 20% coarse to very coarse (0.38-3.00 mm) semi-rounded to angular crystals of quartz, feldspars, and amphiboles within a fine-grained matrix. Concentrations of silicon, iron, manganese, aluminum, mercury, chromium, cadmium, and lead were reported to exceed recommended daily allowances. Specific numerical concentrations were not reported in the abstract.
Why it matters
This study documents that earth materials sold for human consumption in this region contain abrasive minerals with high Mohs hardness (6-7) and hazardous heavy metals, indicating potential risks for dental wear, gastrointestinal injury, and systemic toxicity.
Limits
The study tested only 12 market samples from a single town. No clinical or biological testing on human consumers was performed, and health risk estimates assumed 100% elemental bioavailability without performing bioaccessibility testing. Specific quantitative elemental measurements were not provided in the abstract.
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