Geophagy: A Risk Factor in Orally Acquired Helminths and Toxic Metals
Keywords:
Geophagy; Hypokalaemia; Hypozincaemia.Abstract
Geophagy, also referred to as earth eating is found in many human societies worldwide including Kenya. Diverse reasons are attributable to geophagous habit. Physiologically, ingestion of geophagic materials is believed to satisfy nutritional deficiencies of iron (Fe), calcium (Ca), Zinc (Zn) and other elements. However, health problems that may be associated with geophagy include helminthic infections, hypokalaemia, hypozincaemia, iron deficiency, tooth wear and intestinal blockage among other effects. This study was undertaken to quantify the risk of both helminth infection and toxic metals associated with geophagy among Kenyan urban population. One (1.0) gram of suspected sample material was digested in 1:1 HNO3 in de-ionised distilled water and analysed for total metal content using atomic absorption spectrophotometer (CTA 2000). Helminth ova were recovered by sugar (S.G 1.300) floatation. Higher means (ova/120 g) were found in samples sold by street vendors in large towns, Nairobi (42.0), Eldoret (50.0), Kisumu (18.9) compared to supermarket (2.0) and rural (Rachuonyo 2.3) samples. Geophagic materials were also found to have high levels of some mineral nutrients and non-nutrient pollutants such as lead (Pb) and cadmium (Cd), negating possible nutritive benefits. Heat-treated (baked), packaged and hygienically handled geophagic materials had lower mean parasite ova/120g.
References
Abrahams P.W., and Steigmajer J. (2003). Soil ingestion by sheep grazing the metal enriched floodplain soils of Mid – Wales, Environmental Geochemistry and Health vol. 25: 17 – 25.
Bailey R.A., Clark H.M., Ferris J.P., and Strong R.L. (1978).Chemistry of the environment. Academic press, London. p.425
Bohn H.L., Mcneal B.L., and O’connor G.A. (1985). Soil Chemistry 2nd ed. John Wiley and Sons, New York. p.311 – 314
Brody T. (1994). Nutritional Biochemistry. Academic Press, London.
Danford D.E., Smith J.C., and Huber A.M. (1982). Pica and the mentally retarded. The American Journal of clinical nutrition, vol. 35: 958 – 967.
Foulkes E.C. (1990). Biological effects of heavy metals vol. 2 CRC Press Inc.
Geissler P.W., Mwaniki D.L, Thiongo F., Michausen K.F. and Friss H. (1998).
Geophagy, iron status and anaemia among primary school children in Western Africa. Trop Med Int health; vol. 3(7): 529 – 534.
Geissler P.W., Shulman C.E., Prince R.J., Mutemi W., Mzani C., Friis H. and Lowe B.(1998b). Geophagy, iron status and anaemia among pregnant women on the coast of Kenya. Trans R Soc Trop Med Hyg; vol. 92(5): 549– 553.
Glickman L.T., Camara A.O., Glickman N.W., Mcabe G.P. (1999). Nematode intestinal parasites of children in rural Guinea, Africa. prevalence and relationship to geophagia. Int. J. Epid. 1999 vol. 28(1): 169 – 174.
GoK.(1997) Kisumu, Rachuonyo, Uasin Gishu District Development Plans 1997 – 2001.
GoK. (2001).Statistical Abstract, CBS, Min. Planning and National Development.
Hooda P.S,, Henry C. J. K., Seyoum T.A., Armstrong L.D.M., and Fower M.B. (2002). The potential impact of Geophagia on the Bioavailability or Iron, Zinc and Calcium in human nutrition. Env. Geochemistry and Health vol. 24:305 – 319.
Markell E.M., and Voge M. (1984). Medical Parasitology 5th Ed. W.B Saunders Co., Philadelphia, USA.p.206- 339.
Mendham J., Denney RC., Barness J.D., and Thomas M. (2000). Vogel Text book of Quantitative Chemical Analysis 6th Ed. Pearson Educational Ltd, New Delhi.
Prasad A.S., Halsted J.A., and Nadimi M. (1961). Syndrome of iron deficiency anaemia, hepatosplenomegaly, hypogonadism, dwarfism and geophagia. American journal of medicine vol. 31: 532 – 546.
Schuette S.A. and Linkswiller K. (1984). Present knowledge in nutrition 5th Ed. The nutrition foundation Inc, Washington D.C., USA.
Sheather A.L. (1923). The detection of intestinal protozoa and mange parasites by floatation technique. J. Comp. Path. Therap. vol.36: 266 – 275.
WHO, (1982). Toxicological Evaluation of certain Food Additives and Contamination, WHO Food Additive Series No.21 Geneva. WHO, (1989). Lead Environmental Health Criteria: 85 Geneva.
