Volume 7, Issue 2, April 2018, Page: 74-85
Mineralogical and Physico-Chemical Characterization of Clayey Materials of Meka'a (West Cameroon) Preliminary Step for Their Utilization for Human Ingestion
Stève Aurèle Douola Ninla, Department of Earth Sciences, Faculty of Sciences, University of Dschang, Dschang, Cameroon
Armand Sylvain Ludovic Wouatong, Department of Earth Sciences, Faculty of Sciences, University of Dschang, Dschang, Cameroon
Serge Tchounang Kouonang, Department of Earth Sciences, Faculty of Sciences, University of Dschang, Dschang, Cameroon; Local Materials Promotion Authority (MIPROMALO), Ministry of Scientific Research and Innovation, Yaounde, Cameroon
Bernard Yerima, Department of Soil Sciences, Faculty of Agronomy and Agricultural Sciences, University of Dschang, Dschang, Cameroon
Daniel Njopwouo, Department of Inorganic Chemistry, Faculty of Sciences, University of Yaoundé I, Yaoundé, Cameroon
Received: Feb. 20, 2018;       Accepted: Mar. 7, 2018;       Published: Mar. 29, 2018
DOI: 10.11648/      View  1981      Downloads  147
Discovery of new geophagic clayey deposit in the locality of Meka'a contributed to the apparition of new species of geophagic clay materials in the local market. Due to the fact that positive or negative effects of geophagia are conditioned by physico-chemical, mineralogical and geochemical properties of the clay soil ingested, it is therefore necessary to mineralogically and physico-chemically characterize these clayey materials in order to ascertain their health implications. X ray diffractometry (XRD), X ray fluorescence (XRF), particles size distribution, pH and cation exchance capacity (CEC) are the main analyses carried out with these materials. The results show that the clayey materials of Meka’a are extremely weathered and maybe as a result of the weathering of ignimbritic flows. Two main species (yellow and red) of this clay soil are identified on the basis of their colour, mineralogy and physico-chemical characteristic. Analysis of samples of these two types of materials shows that Meka’a clayey materials are mainly made up of kaolinite (64-87%) and goethite (6-25%). These two minerals greatly influence the properties of these materials. Abundance of kaolinite in this clayey mineral assemblage could be of benefit in the protection of gastro intestinal tract resulting from ingestion of soils with high clay content. These clayey soils have a lower CEC and cannot cause cations deficiency in the digestive tract. Their acidic pH makes them suitable for use as remedy for relief of nausea and to curb salivation associated with pregnancy. No dental enamel or gastro-intestinal tract damage was to be feared when ingesting Meka’a clayey soils and their great abundance in Zn could be of benefit to geophagic individuals. However, possibility of Fe supplementation of the clayey soils of Meka’a may be very low considering low ferric hydroxide content and the fact that only a part of Fe present in the clayey soil can be released in the digestive tract.
To cite this article
Stève Aurèle Douola Ninla, Armand Sylvain Ludovic Wouatong, Serge Tchounang Kouonang, Bernard Yerima, Daniel Njopwouo, Mineralogical and Physico-Chemical Characterization of Clayey Materials of Meka'a (West Cameroon) Preliminary Step for Their Utilization for Human Ingestion, Earth Sciences. Vol. 7, No. 2, 2018, pp. 74-85. doi: 10.11648/
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Mcloughlin, I. J. 1987. The pica habit. Hosp. Med. (37): 286-290.
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 J. Biotech; 9(47): 8058–8067.
Tayie, F. A. Koduah, G., SAP Mork, (2013) Geophagia clay soil as a source of mineral nutrients and toxicants. African journal of food agriculture nutrition and development, 13(1), pp 7157-7170.
Abrahams, P. W. Davies, T. C. Solomon, A. O. Trow, A. J. Wragg, J. (2013) Human geophagia, Calabash chalk and Undongo: Mineral element nutritional implications. PloS ONE, 8(1):e53304. Doi: 10.1371/journal. pone0053304.
Rautureau, M. Allègre, J. Liewig, N. et Katouzian-Safadi, M. (2008) Géophagie: pica, pharmacophagie ou nécessité vitale. Réunion des Sciences de la Terre, Nancy. 6e colloque du groupe français des argiles.
Hunter, J. M. (1993) Macroterm geophagy and pregnancy clays in Southern Africa. J Cultural Geography (14): 69- 92.
Morgan, R. F. (1984) Pica. JR Soc. Med. (70):1052-1054.
Vermeer, D. E. & Ferrell, Jr R. E. (1985) Nigerian geophagical clay: a traditional anti-diarrhoeal pharmaceutical Science (227): 634–636.
Njopwouo, D. Tejiogap, E. Sondag, F. Volkoff, B. et Wandji, R. (1998) Caractéristiques minéralogiques et chimiques des argiles consommées par géophagisme au Cameroun. Ann. Fac. Sci. Univ. Yaoundé I. 31 (2): 319-334.
Dominy, N. J. Davoust, E. and Minekus, M. (2004) Adaptive function of soil consumption: an in-vitro study modeling the human stomach and small intestine. J. Experimental Biology 207: 319-324.
Gomes, C. S. F. and Silva, J. B. P. (2007) Minerals and clay minerals in medical geology. Applied Clay Science. 36(1–3): 4–21.
Douola Ninla, S. A. (2008) Etude géologique et caractérisation minéralogique et chimique des matériaux argileux de Meka'a (Foréké-Dschang). Thèse non publiée Master of Science. Département des sciences de la terre, université de Dschang. 70 p + annexes.
Ngole, V. M. Ekosse, G. E. (2012) Physico-chemistry, mineralogy and geochemistry of geophagic clayey soils from Eastern Cape, South Africa, and their nutrient bioaccessibility. J. Sci. Res. Essays (7): 1319–1331.
Mahaney, W. Hancock, R. G. V. Inoue, M. (1993) Geochemistry and clay mineralogy of soils eaten by Japanese macaques. Primates (34): 85–91.
Mahaney, W. C. Hancock, R. G. V. Aufreiter, S. Huffman, M. A. (1996) Geochemistry and clay mineralogy of termite mound soil and the role of geophagy in chimpanzees of the Mahale Mountains, Tanzania, Primates (37): 121–143.
Hooda, P. S. Henry, C. J. K. Seyoum, T. A. Armstrong, L. D. M. Fowler, M. B. (2002) The potential impact of geophagia on the bioavailability of iron, zinc and calcium in human nutrition. Environmental Geochemistry and Health, 24(4): 305-319.
Wilson, M. J. (2003) Clay mineralogical and related characteristics of geophagic materials. J. Chem. Ecol. (29): 1525–1545.
Abrahams, P. W. (1997) Geophagy (soil consumption) and iron supplementation in Uganda. Trop. Med. Int. Health (2): 617–623.
Aufreiter, S. Hancock, R. G. V. Mahaney, W. C. Stambolic-Robb, A. Sanmugadas, K. (1997) Geochemistry and mineralogy of soils eaten by humans. Int. J. Food Sci. Nutr. (48): 293–305.
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.
Xue-Cun, C. Tai-An, Y. Jin- Sheng, H. Qiu-Yan, M. Zhi- Min, M Li-Xiang (1985) Low levels of zinc in hair and blood, pica, anorexia and poor growth in Chinese preschool children. Am J. Clin. Nutr. (42):694-700.
Mogongoa, L. F. Brand, C. E. De Jager, L. Ekosse, G. E. (2011) Haematological and iron status of QwaQwa women in South Africa. Medical Technology SA. 25(1): 33-37.
Mokhobo, K. P. (1986) Iron deficiency, anaemia and pica. S. Afr. Med. J. (70): 473-481.
Stokes, T. (2006) The earth eaters. Nature (444): 543-544.
Abrahams, P. W. (2012) Involuntary soil ingestion and geophagia: A source and sink of mineral nutrients and potentially harmful elements to consumers of earth materials. Applied Geochemistry (27): 954-968.
Glickman, L. T. Chaudry, I. H. Costantino, J. Clack, F. B. Cypress, R. H. Winslow, L. (1981) Pica patterns, toxocariasis and elevated blood lead in children. Am J Trop Med Hyg. (30): 191-195.
Willhite, C. C., Ball, G. L., McLellan, C. J. (2012) Total allowable concentrations of monomeric inorganic aluminium and hydrated aluminium silicates in drinking water. Crit Rev Toxicol. 42(5): 358-442.
Bisi-Johnson, M. A. Obi, C. L. Ekosse, G. E. (2010) Microbiological and health perspectives of geophagia: An overview. African Journal of Biotechnology 9 (19): 5784-5791.
Barker, O. B. (2005) Tooth wear as a result of pica. British Dental Journal (199): 271-273.
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.
Henry, J. M. and Cring, F. D. (2013) Geophagy: An Anthropological perspective. In Soils and Human Health; Brevik, E. C., Burgess, L. C., Eds.; CRC Press: Boca Raton, FL. USA: 179–199.
Saathoff, E. Olsen, A. Kvalsvig, J. D. Geissler, P. W. (2002) Geophagy and its association with geohelminth infections in rural schoolchildren from northern KwaZulu Natal-South Africa. Trans. Roy. Soc. Trop. Med. Hyg. (96): 485–490.
Bethony, J. Brooker, S. Albonico, M. Geiger, M. S. Loukas, A. Diemert, D. Hotez, J. (2006) Soil transmitted helminth infections: ascariasis, trichuriasis, and hookworm. Lancet 367: 1521–1532.
Anonymous, (2009) Schistosomiasis Research Group General parasitology research: platyhelminthes, trematodes, cestodes and nematodes. Available at
Woywodt, A. & Kiss, A. (2002) Geophagia: the history of earth-eating. J. R. Soc. Med.95(3): 143-146.
Walker, A. R. P. Walker, B. F. Sookaria, F. I., Canaan, R. J. (1997) Pica. J. Roy health (117): 280-284.
Ngole, V. Ekosse, G. E. De Jager, L. Songca, P. S. (2010) Physicochemical characteristics of geophagic clayey soils from South Africa and Swaziland. African Journal of Biotechnology, 9(36): 5929-5937.
Ngole-Jeme, V. M. & Ekosse, G. I. E. 2015. A Comparative Analyses of Particle size distribution, Mineral Composition and Major and Trace Element Concentrations in Soils Commonly Ingested by Humans. Int. J. Environ. Res. Public Health (12): 8933-8955. Doi: 10.3390/ijerph120808933.
Vermeer, D. E. & Frate, D. A. (1979) Geophagia in rural Mississippi; Environmental and cultural context and nutritional implications. Am J. Clin Nutr. (32):2129- 2133.
Tetteh, D. (1993) Percentage oxide content of selected local raw materials. Council for Scientific and Industrial Research (CSIR) publication.
Twenefour, D. (1999) Study of clay eating among lactating and pregnant women in the greater accra region and associated motives and effects. A BSc. project report submitted to the Department of Nutrition and Food Science, University of Ghana.
Tayie, F. A. K. & Lartey, A. (1999) Pica practice among pregnant Ghanaians: Relationship with infant birth-weight and maternal haemoglobin level. Ghana Medical Journal (33):67-76.
Woode, A. & Hackman-Duncan, S. F. (2014) Risks associated with geophagia in Ghana. Can. J. of Pure and applied Sciences 8(1): 2789-2794.
Wouatong, A. S. L. Douola Ninla, S. A. Yongue Fouateu, R. Tématio, P. Njopwouo, D. (2008) Etude géologique et caractérisation minéralogique et chimique des argiles de Meka'a (Foréké-Daschang; Ouest-Cameroun). Actes Conférence sur les matériaux argileux d'Afrique Centrale. Yaoundé 19-22 Novembre 2008: 26-27.
Diko, M. L. & Ekosse, G. E. (2014) Soil Ingestion and Associated Health Implications: A Physicochemical and Mineralogical Appraisal of Geophagic Soils from Moko, Cameroon. Ethno Med. 8(1): 83-88.
Morin, S. (1988) Les dissymétries fondamentales des Hautes Terres de l’Ouest Cameroun et leurs conséquences sur l’occupation humaine. Exemple des Monts Bambouto. In « l’Homme et la montagne tropicale », éd. Séparit, Bordeaux: 35-56.
Nni, J. & Nyobe, J. B. (1995) Géologie et pétrologie des laves précaldériques des monts Bambouto: Ligne du Cameroun. Geochemica Brasiliensis, 9 (1): 47-59.
Youmen, D. (1994) Evolution volcanique, pétrographique et temporelle de la caldeira des monts Bambouto (Cameroun). Thèse Doc. non publiée Univ. Kiel Allemagne. 273p. + annexes.
Ngounouno, I. (1998) Chronologie, pétrologie et cadre géodynamique du magmatisme cénozoïque de la Ligne du Cameroun. Géosciences au Cameroun, Vicat et Bilong éd., collect. GEOCAM, 1/1998, Press. Univ. Yaoundé: 169-184.
Nono, A. Njonfang, E. Kagou Dongmo, A. Nkouathio, D. Tchoua, F. M. (2004) Pyroclatic deposits of the Bambouto volcano (Cameroon Line, Central Africa): evidence of a strombolian initial phase. Journ. African Earth Sci. (39): 409-414.
Gountie Dedzo, M. Nono, A. Njonfang, E. Kamgang, P. Zangmo Tefogoum, G. Kagou Dongmo, A. Nkouathio, D. G. (2011) Le volcanisme ignimbritique des monts Bambouto et Bamenda (Ligne du Cameroun, Afrique Centrale): signification dans la genèse des caldeiras. Bulletin de l’Institut Scientifique Rabat, section Sciences de la Terre. (33): 1-15.
Gountié, Dedzo M. Njonfang, E. Nono, A. Kamgang, P. Zangmo Tefogoum, G. Kagou Dongmo, A. Nkouathio, D. G. (2012) Dynamic and evolution of the Mounts Bamboutos and Bamenda calderas by study of ignimbritic deposits (West-Cameroon, Cameroon Line). Syllabus Review, Sci. Ser. (3): 11–23.
Bouyo Houketchang, M. (2001) Etude pétrographique des fenêtres de socle de la ville de Dschang et ses environs (Ouest –Cameroun). Mémoire de maîtrise non publié, Département des sciences de la terre, université de Dschang. 55 p. + annexes.
Bouyo Houketchang, M. (2003) Etude tectonique et métamorphique de la région de Dschang (Ouest Cameroun). Mémoire DEA non publié Département des sciences de la terre, université de Yaoundé I. 46 p. + annexes.
Kwékam, M. (2005) Genèse et évolution des granitoïdes calco-alcalins au cours de la tectonique panafricaine; Le cas des massifs syn à tardi tectonique de l’Ouest Cameroun (Région de Dschang et de Kékem. Thèse Doct. d’Etat non publié, université de Yaoundé 1. 175 p. + annexes.
Mosser-Ruck, R. Devineau, K. Charpentier, D. Cathelineau, M. (2005) Effects of ethylene glycol saturation protocols on XRD patterns: a critical review and discussion. Clays and Clay Minerals, 53(6): 631-638.
Tchoua, F. M. (1973) Sur l’existence d’une phase initiale ignimbritique dans le volcanisme des monts Bambouto (Cameroun). Comptes Rendus de l’Academie des Sciences Paris (276): 2863–2866.
Poueme Djueyep, G. (2012) Caractérisation minéralogique et géotechnique des matériaux d’altération développés sur les ignimbrites de Dschang (Ouest-Cameroun): valorisation dans le bâtiment. Thèse non publiée Master of Science. Departement des Sciences de la TerreUniv. Dschang (Cameroun). 105 p.+ annexes.
Banenzoué, C. Djoufac, E. W. Njopwouo, D. et Wandji, R. (2001) Caractère antiacide de quelques argiles consommées par géophagie au Cameroun. Actes de la première conférence sur la valorisation des matériaux argileux au Cameroun et de la création du groupe camerounais des argiles: 215-223.
Mahaney, W. C. Milner, M. W. Mulyono, H. S. Hancock, R. G. V. Aufreiter, S. Reich, M. Wink, M. (2000) Mineral and chemical analyses of soils eaten by humans in Indonesia. Int. J. Environ. Health (10): 93–109.
Odewumi, S. C. (2013) Mineralogy and Geochemistry of Geophagic Clays from Share Area, Northern Bida Sedimentary Basin, Nigeria. J. Geol. Geosci. (2) 108: doi: 10.4172/2329-6755.1000108.
Nesbitt, H. W. & Young, G. M. (1982) Early Proterozoic climates and plate motions inferred from major element chemistry of luttites Nature (291): 715–717.
Harnois, L. (1988) The CIW index: A new chemical index of weathering. Sediment. Geol. (55): 319–322.
Underwood, E. J. (1971) Trace elements in human and animal nutrition. Academic Press. London, 4th edit. 500 p.
Fotio, D. Matettsa, T. E. M. Signing, P. Njopwouo D et Wandji, R. 2001. Enrichissement en zinc de quelques argiles consommées par géophagie au Cameroun. Actes de la première conférence sur la valorisation des matériaux argileux au Cameroun et de la création du groupe camerounais des argiles: 225-234.
Brouillard, M. Y. & Rateau, J. G. (1989) Smectite and kaolin on bacterial enterotoxins. Gastroen. Clin. Biol. (13): 18–24.
Severance, H. W. Holt, T. Patrone, N. A. Chapman, L. (1998) Profound muscle weakness and hypokalemia due to clay ingestion. S. Med. J. (18): 272–274.
Abrahams, P. W. and Parsons, J. A. (1997) Geophagy in the tropic: an appraisal of three Geophagic materials. Environmental Geochemistry and Health 1(9): 19-22.
Omen, A. G. Sips, A. J. Groten, A. M. Dick, J. P. Sijm, T. J. M. (2000) Mobilization of PCBs and lindane from soil during in vitro digestion and their distribution among bile salt micelles and proteins of human digestive fluid and the soil. Environ Sci Technol (34): 297-303.
Ibeanu, G. E. L. Dim, L. A. Mallam, S. P. Akpa, T. C. Munyithya, J. (1997) Nondestructive XRF analysis of Nigerian and Kenyan clays. J Radioanal Nucleic Chem (221): 207-209.
Eigbike, C. O. Nfor, B. N. Imasuen, I. O. (2013) Physico Chemical Investigations and Health Implications of Geophagial Clays of Edo State, Mid-Western Nigeria. J. Geol Geosci (3): 140. Doi: 10.4172/2329-6755.1000140.
Okereafor, G. Uchenna, Mavumengwana Vuyo, Mulaba-Bafubiandi, F. A. (2016) Mineralogical Profile of Geophagic Clayey Soils Sold in Selected South African Informal Markets. Int'l Conf. on Advances in Science, Engineering, Technology & Natural Resources (ICASETNR-16) Nov. 24-25, Parys (South Africa): 191-197.
Kikouama, O. J. R. Konan, K. L. Bonnet, J. P. Baldé, L. Yagoubi, N. (2009) Physicochemical characterization of edible clays and release of trace elements. Appl. Clay Sci. (43): 135–141.
Brevik, E. C. Burgess, L. C. (2013) Soils and human health: An overview. In Soils and Human Health; Brevik E. C., Burgess L. C., Eds.; CRC Press: Boca Raton, FL. USA: 29–56.
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