THE IDENTIFICATION OF GEOPHAGIA BY NEUTRON-ACTIVATION ANALYSIS

Chemical markers for use as indicators of geophagia in Jamaica is repo rted, Five volunteers each ingested 10 g of each of three common soils of Jamaica to which carmine (an inert gastrointestinal dye) had been added. A pre-ingestion faecal sample and all post-ingestion faecal sam ples were collected until no more carmine was seen. The faecal and soi l samples were analysed by instrumental neutron activation analysis. O f the 14 elements quantified, Dy, Eu, Ce, Hf, and Th were consistently delected in the post-ingestion but not in the pre-ingestion faecals. These elements should therefore be excellent markers of geophagia as t hey are present in insignificant levels in food compared to soils. Bec ause of high sensitivity and short throughput times, Dy and Eu appear to be the most promising elements for the detection of the occurrence of geophagia.