GEOCHEMISTRY AND MINERALOGY OF SOILS EATEN BY HUMANS

Earth samples (soils and parent materials) eaten by humans on three co ntinents were analyzed chemically and mineralogically. Samples from Ch angsha county, China, are from three sites and were used as recently a s the 1950s as famine food; soil from a site in North Carolina, USA wa s consumed for general health benefits; samples from Zimbabwe are stil l used as medicine for digestive problems (diarrhea). In each case, it is 'common knowledge' that the geophagy is beneficial. Chemical analy sis of the soils and of soil extracts, and mineralogical analysis of t he soils, reveal patterns of element levels and clay minerals relative ly consistent with the effects desired or reported by consumers. There are important parallels between geophagy in humans and in animals, in particular the apparent quest for dietary/nutritional and pharmaceuti cal benefits.