Quantification of Selected Essential and Toxic Minerals in Geophagic Materials in Kiambu County, Kenya
Kamau, Tabitha Wanjiru
MetadataShow full item record
Pica is described as the craving and subsequent consumption of non-food substances including earth, charcoal and uncooked rice. Various hypothesis have been fronted to explain pica among them hunger, micronutrient deficiency and protection. Geophagy, a special type of pica applicable to the deliberate consumption of soil and clay deposits cuts across socio-economic, ethnic, religious and racial divides due to cultural, medicinal, physiological and nutritional factors. In sub-Saharan Africa, its popularity has been increasing overtime especially among pregnant women and children under the age of five. Kenya has the highest prevalence rate (89.8%) of the geophagic practice as compared to other African countries. In Kiambu County, an upward trend has been exhibited in the sales made from geophagic materials. With the increase in the geophagic practice in Kiambu County, it is necessary to investigate potential benefits and/or dangers of the materials consumed with respect to their essential and toxic minerals level. The study aimed at examining the levels of essential minerals (Ca, Mg, Fe, Mn and Zn) and toxic minerals (Al, Si and Pb) in geophagic materials from Kiambu County. They were purposively sampled from eight quarry mines, four brands in supermarkets, and yellow and white colours in open-air markets and analyzed using Atomic Absorption Spectroscopy (AAS). The data was analyzed using Analysis of Variance (ANOVA) and t-test. The range was found to be ND - 27.9±0.02 (Ca), ND - 0.18±0.00 (Mg), 0.42±0.00 - 4.83±0.02 (Fe), ND - 0.23±0.03 (Mn) 64.6±0.35 - 233.0±0.89 (Al) and 184.1±0.14 – 291.8±0.34 mg/g (Si). The concentration of Zn and Pb was 10.89+0.32 - 161.67+0.03 and 1.09+0.02 - 79.67+0.04 ppm respectively. Most of the minerals varied significantly (α=0.05) and could be due to differences in their origin. Comparing essential minerals level to Recommended Daily Intakes (RDI) while assuming a 50.0% bioavailability indicated that the minerals were not present in appreciable amounts and therefore have negligible contribution (except for Fe in all the three sources and Mn in some of the sources). For toxic minerals, Al obtained from the three sources was below World Health Organization (WHO) and European Food Safety Authority (EFSA) limits. However, Si and Pb levels were found to be above the WHO/EFSA which has the potential of endangering the health of the individual. With an exception of Fe and Mn, findings point to fears of toxicity. Therefore, there is need to discourage the practice as geophagic individuals expose themselves to health risks associated with toxicity.