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Microbial Evaluation of Geophagic and Cosmetic Clays from Southern and Western Nigeria: Potential Natural Nanomaterials

Authors: Mary A. Bisi-Johnson, Kehinde A. Adediran, Saheed A. Akinola, Hamzat A. Oyelade


Geophagic and cosmetic clays are among potential nanomaterial which occur naturally and are of various forms. The use of these nanoclays is a common practice in both rural and urban areas mostly due to tradition and medicinal reasons. These naturally occurring materials can be valuable sources of nanomaterial by serving as nanocomposites. The need to ascertain the safety of these materials is the motivation for this research. Physical Characterization based on the hue value and microbiological qualities of the nanoclays were carried out. The Microbial analysis of the clay samples showed considerable contamination with both bacteria and fungi with fungal contaminants taking the lead. This observation may not be unlikely due to the ability of fungi species to survive harsher growth conditions than bacteria. ‘Atike pupa’ showed no bacterial growth. The clay with the largest bacterial count was Calabash chalk (Igbanke), while that with the highest fungal count was ‘Eko grey’. The most commonly isolated bacteria in this study were Clostridium spp. and Corynebacterium spp. while fungi included Aspergillus spp. These results are an indication of the need to subject these clay materials to treatments such as heating before consumption or topical usage thereby ascertaining their safety.

Keywords: Nanomaterial, Quality, Microorganism, Clay

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[1] S. Guggenheim, R. T. Martin. "Definition of clay and clay mineral, Joint report of the AIPEA nomenclature and the CMS nomenclature Committees”. Clay Clay Minerals, vol. 43: pp 255-256, 1995.
[2] J. A. Halsted. "Geophagia in man: Its nature and nutritional effects”. American J. Nutrition, vol. 21, pp 1384-1393, 1968.
[3] N. J. Dominy, E. Davoust, M. Minekus, "Adaptive function of soil consumption: an in vitro study modelling the human stomach and small intestine,” J. Exp. Biol., vol. 207, pp 319-324, 2004.
[4] G. George, E. Ndip, "Prevalence of Geophagia and its possible implication to health- A study in rural South Africa,” in International conference on Environmental Health and Development. ICPBEE Vol 4, 2011. LACSIT PRESS, Singapore.
[5] M. A. Bisi-Johnson, C. L. Obi, G. E. Ekosse, "Microbiological and health related perspectives of geophagia: An overview.” Afr. J. Biotechnol. Vol. 9, no. 19, pp 5784-5791, 2010.
[6] S. C. Sheppard, "Geophagy: Who eats the soils and where do possible contaminants go?” Environ. Geology, vol. 33, 109-114, 1998.
[7] P. W. Geisller, R. J. Prince, M. Levene, C. Poda, S. E. Beckerly, W. Mutemi, C. E. Schulman, "Perception of soil eating and anemia among pregnant on the Kenyan coast.” Soc. Sci. Med., vol. 48, no. 8, pp 1069-1079, 1999.
[8] E. Rose, J. Porcerelli, A. Neale, "Pica: Common but commonly missed” J Chemical Ecol., vol. 29, no. 7, pp 1525-1547, 2000.
[9] C. O. Izugbara, "The cultural context of geophagy among Pregnant and lactating Ngwa women in south eastern Nigeria.” African Anthropol. Vol. 10, no. 2, pp 180-199, 2003.
[10] P. W. Abrahams, J. A. Parsons, "Geophagy in the tropics: An appraisal of three geographical materials.” Environ. Geochem. Health vol. 19, pp 19-22, 1997.
[11] G. Klaus, B. Schmid, "Geophagy at natural licks and mammal ecology; A review,” Mammali, vol. 62, pp 481-497, 1998.
[12] R. Krishnamani, W. C. Mahaney. Geophagy among primates: Adaptive significance and ecological consequences. Animal Behaviour. vol. 55, pp 899-915, 2000.
[13] W. J. P. Harvey, P.B. Dexter, I. Darton-Hil, "The Impact of Consuming Iron from Non –Food sources on Iron –status in Developing Countries.” Pub. Health Nutrition, vol. 3, no. 4, pp 375-383, 2000.
[14] G. N. Callahan, "Eating Dirt.” Emerg. Infect. Dis., vol. 9, no. 8, pp 1016- 1021, 2003.
[15] M. Price, "Cosmetics, Styles & Beauty Concepts in Iran.” 2001. Available online: cosmetics_beauty.php. Accessed September 20, 2012.
[16] A. Claeyssens, "The History of Cosmetics and Makeup.” 2009. Available online at Accessed September 10, 2012.
[17] M. I. Carretero, "Clay minerals and their beneficial effects upon human health. A review.” Applied Clay Sci. vol. 21, pp 155–163, 2002.
[18] W. C. Mahaney, M.W. Milner, H. S. Mulyono, R. G. V. Hancock, S. Aufreiter, M. Reich, M. Wink, "Mineral and chemical analyses of soils eaten by humans in Indonesia.” Int. J. Environ. Health, vol. 10, pp 93-109. 2000.
[19] M. Fletcher, Bacterial adhesion: Molecular and Ecological Diversity. Wiley-Liss, New York, 1996.
[20] C. Gay, L. Lieblier, "On Stickiness.” Phys. Today. Vol. 52, pp 48-52, 1999.
[21] S. K. Lower, C. J. Tadanier, M. F. Hochella Jr, "Measuring interfacial and adhesion forces between bacteria and mineral surfaces with biological forcemicroscopy.” Geochem. Cosmochimica Acta. Vol. 64, no. 18, pp 3133-3139, 2000.
[22] L. Huang, D. Q. Li, Y. J. Lin,, M. Wei, D. G. Evans, X. Duan, "Controllable preparation of nano-MgO and investigation of its bactericidal properties.” J. Inorganic Biochem. Vol. 99: pp 986–993, 2005.
[23] J. Sawai, H. Kojima, H. Igarashi, A. Hashimoto, S. Shoji, T. Sawaki, "Antibacterial characteristics of magnesium oxide powder.” World J. Microbiol. Biotechnol. Vol. 16: pp 187–194, 2000.
[24] O. Yamamoto, J. Sawai, T. Sasamoto, "Change in antibacterial characteristics with doping amount of ZnO in MgO–ZnO solid solution.” Int. J. Inorganic Material, vol. 2: pp 451–454, 2000.
[25] O.B. Koper, J.S. Klabunde, G.L. Marchin, K. J. Klabunde, P. Stoimenov, L. Bohra, " Nanoscale powders and formulations with biocidal activity toward spores and vegetative cells of bacillus species, viruses, and toxins.” Current Microbiol., vol 44: pp 49–55, 2002.
[26] Calabi M, Jara A, Bendall J, Welland M, de la Luz Mora M, "Structural characterization of natural nanomaterials: potential use to increase the phosphorus mineralization, in 19th World Congress of Soil Science, Soil Solutions for a Changing World 1 – 6 August 2010, Brisbane, Australia. Published on DVD. pp 29-32.
[27] W. A. Rutala, D. J. Weber, the Healthcare Infection Control Practices Advisory Committee (HICPAC), "Guideline for disinfection and sterilization in Healthcare facilities.” Centers for Disease Control and prevention, 2009. 1600 Clifton Road, Atlanta, GA30333. Available at Accessed on August 26, 2013.
[28] Munsell Soil Colour Book. The Munsell soil colour book, Colour charts. Munsell Colour Company Inc., 1994.
[29] V. M. Ngole, G. E. Ekosse, L. de Jager, S. P. Songca, "Physicochemical characteristics of geophagic Clayey soils from south Africa and Swaziland,” Afr. J. Biotechnol., vol. 9, no. 36, pp 5929-5930, 2010.
[30] A. Momoh, T. C. Davies, H. A. Akinsola, B. Iweriabor, J. Nwobegahay , T. Nifefe, "Physical features and Occurrence of beneficial bacteria in Edible clays from Vhembe District, South Africa,” in 1st Conference on Clay and Clay Mineral: An innovative perspective on the role of clays and clay minerals and Geophagia on Economic Development, Free State University, Bloemfontein, South Africa. 2011, pp 306-313.
[31] M. J. Wilson, "Clay Mineralogical and related characteristics of geophagic materials.” J. Chem. Ecol., vol. 29, no. 7, pp 1525-1547, 2003.
[32] S. L. Young, M. J. Wilson, S. Hillier, E. Delbos, S. M. Ali, R. Stoltzfus. "Difference and commonalities in physical, Chemical and Mineralogical Properties of Zanzibari Geophagic Soils.” J Chem. Ecol., vol. 36, pp 129-140, 2010.
[33] S. F. Mpuchane, G. E. Ekosse, B. A. Gashe, I. Morobe, S. H. Coetzee. "Microbiological characterization of southern African medicinal and cosmetic clays,” Int. J. Env. Health Res., vol. 20, no. 1, pp 27-41, 2010.
[34] O. A. Okunlola, K. A. Owoyemi, "Compositional Characteristics of Geophagy in parts of Nigeria,” in 1st Conference on Clay and Clay Mineral: An innovative perspective on the role of clays and clay minerals and Geophagia on Economic Development, Free State University, Bloemfontein, South Africa pp, 290-305, 2011.
[35] J. R. Kikouma, F. Le Cornec, S. Bouttier, A. Launay, L. Balde, N. Yagoubi, "Evaluation of Trace elements released by edible clays in physicochemically simulated physiological media.” Int. J. Food Sci. Nutrition, vol. 60, no. 2, pp 130-142, 2009.