Assessing the Bioavailability of some Trace and Major Elements in Geophagical Clays of South-Western and Eastern Nigeria: An Invitro Study
Geophagy is the deliberate ingestion of soil. This study aims to assess the bioavailability of some trace and major elements in the edible clays of southern parts of Nigeria; in order to ascertain the essential elements and possible potential harmful elements that is bioaccessible and bioavailable to the geophagists. Raw and roasted samples were collected at the mining sites and from market vendors in Aforwa, Ohordua, Uzalla and Nteje. Physiochemical, geochemical and mineralogical compositions were quantified using various analytical equipment. The bio-accessible contents of some trace and major elements were determined by invitro bio accessibility tests that mimic the conditions of the human gastrointestinal environments. The colour of the clays ranges from whitish, to grey; the materials are dominantly clayey size particles. The pH is acidic with moderate to low CEC in all the samples (2.84 meq/100g). A range of elements was identified. The geophagic materials are majorly kaolinite, with other range of minerals like quartz, goethite, hematite. The concentration of the bio accessible elements in the 2-part acidalkaline invitro physiologically based test at 5g dose shows low bio accessibility of most elements but at higher dose of 20 g, the concentrations of the bio-accessible elements in the roasted samples were increased supplying 0.07-80% (Fe>Cu>Zn>Mn>Ca>Mg>P>K) nutrients based on the reference nutrients intake required by the geophagists. The Nteje clays are the highest supplier while, the Ohordua is the least supplier of both the trace and major elements, hence the edible clays are a moderate source of mineral nutrients and potential source of potential harmful elements (V, Ni, Cr, and Pb), and if consumed in excess or even at lower concentration may pose toxic effects to the consumers. Moderate dose of this material that is within and/or below the Safe Upper levels should be consume since geophagy has become inherent to human.
Abrahams, P.W., Davies, T.C., Solomon, A.O., Trow, A.I., Wragg, J., 2013. Human geophagia calabar chalk and undongo: mineral element nutritional implication. PLoS One 8 (1), e53304.
Akujieze, C.N., 2004. Effect of Anthropogenic Activities on Urban Groundwater System and Aquifer Vulnerability Assessment in Benin City, Edo State Nigeria. PhD Thesis University of Benin,Benin City, Nigeria.
Alloway, B.J., 1990. Heavy Metals in Soil, Blackie, Glasgow. Aufreiter, S., Hancock, R.G., Mahaney, W.C., Stamolic-Robb, A., Sanmugadas, K., 1997. Geochemistry and mineralogy of soils eaten by humans, International Journal of Food Sciences and Nutrition 48, 293-305.
Barker, O.B., 2005. Tooth wear as a result of pica. British Dental Journal 199, 271-273.
Cavallaro, N., McBride, M.B., 1984. Zinc and copper sorption and fixation by acid clay: effect of selective dissolutions. Soil Science Society of America Journal 48, 1050-1054.
Daugherty, A.L., Mrsny, R.J., 1999. Transcellular uptake mechanisms of the intestinal epithelial barrier – Part one.
Pharmaceutical Science & Technology Today 2, 144-151.
Department of Health, 1991. Dietary Reference Values for Food Energy and Nutrients for the United Kingdom. HMSO, London.
Diamond, J.M., 1999. Dirty eating for healthy living. Nature 400, 120-122.
Diko, M.L., Siewe, C.N., 2014. Physico-chemistry of geophagic soils ingested to relief nausea and vomiting during pregnancy. African Journal of Traditional Complementary and Alternate Medicine 11 (3), 21-24.
Dominy, N.J., Davoust, E., Minekus, M., 2004. Adaptive function of soil consumption: an in vitro study modeling the human stomach and intestine. Journal of Experimental Biology 207, 319-324.
Ekosse, G.E., Anyangwe, S., 2012. Mineralogical and particulate morphological characterization of geophagic clayey soils from Botswana. Bulletin of the Chemical Society of Ethiopia 26 (3), 373-382.
Ekosse, G.E., de Jager, L., Ngole, V., 2010. Traditional mining and mineralogy of geophagic clays from Limpopo and Free State Provinces. South Africa. African Journal of Biotechnology 9 (47), 8058-8067.
Expert Group on Vitamins and Minerals, 2003. Safe upper levels for vitamins and minerals. Food Standards Agency. Available at: www.food.gov.uk/multimedia/pdfs/vitmin2003.pdf.
Foster, J.W., 1995. Pica. East African Medical Journal 4, 68-76. Geissler, P.W., Mwaniki, D.L., Thiong_O.F., Friis, H., 1997. Geophagy among school children in western Kenya. Tropical Medicine and International Health 2, 624-630.
Gelfand, M., 1945. Geophagy and its relation to hookworm disease. East African Medical Journal 22, 98-103.
Gillman, G.P., Sumpter, E.A., 1986. Modification to the compulsive exchange method for measuring exchange
characteristics of soils. Australian Journal of Soil Research 24 (1), 61-66.
Ibeanu, G.E.L., Dim, L.A., Mallam, S.P., Akpa, T.C., Munyithya, J., 1997. Non-destructive XRF analysis of Nigerian and Kenyan clays. Journal of Radioanalytical and Nuclear Chemistry 221 (1-2), 207-209.
Johns, T., Duquette, M., 1991a. Detoxification and mineral supplementation as functions of geophagy. The American Journal of Clinical Nutrition 53 (2), 448-456.
Johns, T., Duquette, M., 1991b. Traditional detoxification of acorn bread with clay. Ecology of Food and Nutrition 25 221-228.
Kogbe, C.A., 1989. The cretaceous and palaeocene sediments of Southern Nigeria. In: C.A. Kogbe (ed.) "Geology of Nigeria", Elizabethan Publ. Co., Lagos, Nigeria, pp 215.
Minnich, V., Okc¸uoglu, A., Tarcon, Y., Arcasoy, A., Cin, S., Yorukoglu, O., Renda, F., Demirag, B., 1968. Pica in Turkey:II effect of clay upon iron absorption. The American Journal of Clinical Nutrition 21, 78-86.
MSCC, 1992. Munsell Soil Color Charts 1992 Revised Edition. Macbeth.
Ngole, V.M., Ekosse, G.E., de Jager, L., Songca, S.P., 2010. Physicochemical characteristics of geophagic clayey soils from South Africa and Swaziland. African Journal of Biotechnology 9 (36), 5929-5937.
Nwajide, C.S., Reijers, T.J.A., 1990. Geology of the southern Anambra Basin. In: Reijers, T. J. A., (ed). Selected Chapters on Geology. Warri: SPDC, 133-148.
Nwajide, C.S., 1979. A lithostratigraphic analysis of the Nanka Sands, South-eastern Nigeria. Journal of Mining and Geology 16, 100-110.
Oliveira, R.N., Acchar, W., Soares, G.D.A., Barreto, L.S., 2013. The increase of surface area of a Brazilian palygorskite clay activated with sulfuric acid solutions using a factorial design. Material Research 16 (4), 924-92.
Palumbo, B., Angelone, M., Bellanva, A., Dazzi, C., Hauser, S., Neri, S., Wilson, J., 2000. Influence of Inheritance and
Pedogenesis on Heavy Metal Distribution in Soils of Sicily, Italy. Geoderma 95 (3-4), 247-266.
Plumlee, G.S., Ziegler, T.L., 2003. The medical geochemistry of dusts, soils, and other earth materials. In: Lollar, B.S. (Ed.), Environmental Geochemistry, Treatise on Geochemistry, vol. 9. Elsevier-Pergamon, Oxford, pp. 263-310 (Chapter 7).
Reyment, RA, 1965. Aspects of the Geology of Nigeria. University of Ibadan Press. 133p.
Smith, B., Rawlins, B.G., Cordeiro, M.J.A.R., Hutchins, M.G., Tiberindwa, J.V., Sserunjogi, L., Tomkins, A.M., 2000. The bioaccessibility of essential and potentially toxic trace elements in tropical soils from Mukono District, Uganda, Journal of the Geological Society, London 57, 885-891.
Soil Survey Laboratory Manual, 1996. United States Department of Agriculture Soil Survey Laboratory Methods Manual, 1996. Particle Size Analysis. Soil Investigation Report No. 42, Version 3.0, pp. 31-111.
Thomson, J., 1997. Anaemia in pregnant women in eastern Caprivi, Namibia. South African Medical Journal 87, 1544-1547.
van Reeuwijk, L.P., 2002. Procedures for Soil Analysis, International Soil Reference and Information Centre (ISRIC)
Technical Paper, No. 9, SRIC, p. 19.
Vaculíková, L., Plevová, E., Vallová, S., Koutník, I., 2011. Characterization and differentiation of kaolinites from selected Czech deposits using infrared spectroscopy and differential thermal analysis. Acta Geodynamica Geomateriala 8 (1), 59-67.
Wragg, J., Cave, M.R., 2003. In-vitro methods for the measurement of the oral bioaccessibility of selected metals and metalloids in soils: A critical review. Environment Agency, R&D Technical Report P5-062/TR/01.
Copyright (c) 2022 Collins O. Eigbike, Isaac O. Imasuen, Festus Obomese, Daniel Imariabe Omoruyi
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License.
The authors keep the copyrights of the published materials with them, but the authors are aggee to give an exclusive license to the publisher that transfers all publishing and commercial exploitation rights to the publisher. The puslisher then shares the content published in this journal under CC BY-NC-ND license.