Overview
Chigona and colleagues estimated intake and health risk from wild fruits, medicinal plants, termites, rodents and a geophagic termite-soil-tree-wrap eaten along Zimbabwe’s Great Dyke and nearby granitic areas, using ingestion rates from key informants. The concentration table for these foods is taken from the authors’ companion paper. The new measurements here are metals released into hot-water infusions of five medicinal plants, analyzed by flame AAS.
Key numbers
- Lead extracted into infusions: Erythrina abyssinica bark 3.33 ± 0.46 mg/kg (Great Dyke) and 1.22 ± 0.14 mg/kg (granitic), Asparagus laricinus roots 5.50 ± 1.02 mg/kg (Great Dyke), expressed per kg of plant (Table 3).
- Cadmium and chromium were not detected (<0.01 mg/kg) in any infusion (Table 3).
- Quoted from the companion paper, not measured here: geophagic termite-soil-tree-wrap lead 5.69 ± 1.02 mg/kg (Great Dyke) and 6.26 ± 0.82 mg/kg (granitic), nickel 449.27 ± 181.8 mg/kg on the Great Dyke (Table 1).
Methods (brief)
Oven-dried, ground plant parts in informant-reported doses were steeped in 300 mL boiled water, and the supernatant was analyzed by flame AAS; results were re-expressed as mg per kg of plant. Detection limit below 0.01 mg/kg. No QA data are reported for the infusions.
Evidence Fitness
The only new occurrence data are the medicinal plant infusions, with no sample counts or QA. The geophagic material values are quotes of the companion study (Sci. Afr. 2026, 32, e03344) and should be cited from that paper, so this source is context, not direct evidence, for clay-geophagy. The Great Dyke is a naturally metal-rich serpentinite belt, so values are not general background.