Maternal geophagy in Ghana: a mini review of toxicological, microbial, nutritional, and radiological exposure pathways

Maternal geophagy remains a common cultural and behavioural practice among pregnant women in Ghana, representing a potential pathway for various concurrent exposures, including toxicological, microbial, nutritional, and radiological. This Mini Review synthesises evidence from a wide range of multidisciplinary literature, encompassing mineralogy, toxicology, parasitology, microbiology, nutrition, and radiological science, to provide a comprehensive assessment of maternal geophagy in the Ghanaian context. The reviewed literature consistently indicates that geophagic clays contain elevated concentrations of toxic metals, such as lead, arsenic, cadmium, chromium, and mercury, which often exceed international safety limits. Bioaccessibility studies further demonstrate that metal solubility increases under gastric conditions, suggesting that actual maternal exposure may be underestimated when only considering total concentrations. In addition to chemical hazards, microbial contamination and the presence of geohelminths in commercially sold clays pose infection risks, exacerbated by informal extraction, processing, and handling practices. Emerging evidence specific to Ghana also shows that commonly consumed clays contain naturally occurring radionuclides, such as potassium-40, uranium-238, and thorium-232, which contribute to measurable internal doses that warrant closer examination, especially with repeated ingestion during pregnancy. Overall, these findings highlight maternal geophagy as a multi-hazard exposure pathway involving toxicological, microbial, nutritional, and radiological risks. Significant knowledge gaps remain, including the lack of bioavailability-adjusted radiological dose modelling and limited longitudinal evidence linking geophagy to foetal outcomes. This review highlights the importance of developing integrated exposure assessment frameworks, enhancing regulatory oversight, and implementing targeted public health interventions to address the multifaceted risks associated with maternal geophagy in Ghana.