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The Influence of Clays on Human Health: A Medical Geology Perspective

Published online by Cambridge University Press:  01 January 2024

Robert B. Finkelman
Robert B. Finkelman*
Affiliation:
Geosciences Department, University of Texas at Dallas, 800 West Campbell Road, Richardson, TX 75080, USA
*
*bobf@utdallas.edu
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Abstract

Clay is unique especially from the perspective of medical geology, that is, the impacts of geologic materials and geologic processes on animal and human health. Clay is the only natural material that can impact human health through all routes of exposure: ingestion, inhalation, and dermal contact. Moreover, these impacts can be harmful as well as beneficial. Ingestion of clay, a form of geophagy, has been practiced for millennia and is still widely practiced today. Humanoids have been ingesting clay for at least two million years to ease indigestion and counteract poisons. Some additional benefits may accrue from eating clays such as providing some nutrients but these benefits are far outweighed by the likely negative consequences such as tissue abrasion, intestinal blockage, anemia, exposure to pathogens and toxic trace elements, and potassium overdose. Inhalation of airborne minerals including clays has impacted the heath of millions. In the 1930s thousands of people living in the Dust Bowl in the U.S. southwest inhaled copious amounts of clay contributing to deadly ‘dust pneumonia.’ Using clay as a poultice to stem bleeding and cure certain skin ailments is an age-old practice that still has many adherents. A classic recent example of the antibacterial properties of clay is the use of certain clays to cure Buruli ulcer, a flesh eating disease. However, walking barefoot on clays in certain volcanic soils can result in non-filarial podoconiosis or elephantiasis. The absence of clays in soils can have serious health consequences. In South Africa, clay-poor soils yield crops lacking in essential nutrients and may be the principal cause of Msileni joint disease. Clearly, a detailed knowledge of the clays in the environment can have significant benefits to human health and wellbeing.

Keywords

GeophagyMseleni Joint DiseasePharmaceuticalsPneumoconiosisPodoconiosisSoil
Type
Research Article
Information
Clays and Clay Minerals , Volume 67 , Issue 1 , 15 February 2019 , pp. 1 - 6
Copyright
Copyright © Clay Minerals Society 2019

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References

Abrahams, P.W. (2002). Soils: their implication to human health. The Science of the Total Environment. 231, 1–32.CrossRefGoogle Scholar
Abrahams, P.W. (2013). Geophagy and the in voluntary ingestion of soil. In: Selinus, O., Alloway, B., Centenoi, J.A., Finkelman, R.B., Fuge, R., Lindh, U., & Smedley, P. (Eds.), Essentials of medical geology: revised edition (pp. 433–454). Dordrecht, The Netherlands: SpringerCrossRefGoogle Scholar
Aguzzi, C., Cerezo, P., Viseras, C., & Carmella, C. (2007). Use of clays as drug delivery systems: Possibilities and limitations. Applied Clay Science, 36, 22–36.CrossRefGoogle Scholar
Berge, W., Mundt, K., Luu, H., & Boffetta, P. (2017). Genital use of talc and risk of ovarian cancer: a meta-analysis. European Journal of Cancer Prevention, 27, 248–257.CrossRefGoogle Scholar
Brevik, E. C. (2013). Climate change, soils, and human health. In: Brevik, E.C. & Burgess, L.C. (Eds.). Soils and Human Health (pp. 345–383). Boca Raton, Florida, USA: CRC Press.Google Scholar
Bunnell, J.E., Price, S.D., Das, A., Shields, T.M., & Glass, G.E. (2003). Geographic information systems and spatial analysis of adult Ixodes scapularis (Acari: Ixodidae) in the middle Atlantic region of the U.S.A. Journal of Modern Entomology, 40, 570–576.CrossRefGoogle ScholarPubMed
Carretero, M.I. (2002). Clay minerals and their beneficial effects on human health: A review. Applied Clay Science, 21, 155–163.CrossRefGoogle Scholar
Ceruti, P.O., Fey, M., & Pooley, J. (2003). Soil nutrient deficiencies in an area of endemic osteoarthritis (Mseleni Joint Disease) and dwarfism in Maputoland, South Africa. In: Skinner, H.C.W. & Berger, A.R. (Eds.). Geology and Health: Closing the Gap (pp. 151–154). New York: Oxford University Press.Google Scholar
Cross, W. (1919). Geology in the World War and after. Bulletin of the Geological Society of America, 30, 165–188.CrossRefGoogle Scholar
Davey, G., Tekola, F., & Newport, M.J. (2007). Podoconiosis: non-infectious geochemical elephantiasis. Intensive and Critical Care Nursing, 101, 1175–1180.Google ScholarPubMed
Dubovsky, H. (1999). Pneumoconiosis and tractor ploughing. South African Medical Journal, 89, 366.Google ScholarPubMed
Egan, T. (2006). The Worst Hard Time. Houghton Mifflin Co. Boston, Massachusetts, USA. 340 p.Google Scholar
Gomes, C.S.F. & Silva, J.B.P. (2007). Minerals and clay minerals in medical geology. Applied Clay Science, 36, 4–21.CrossRefGoogle Scholar
Gordon, R.E., Fitzgerald, S., & Millette, J. (2014). Asbestos in commercial cosmetic talcum powder as a cause of mesothelioma in women. International Journal of Occupational and Environmental Health, 20, 318–332.CrossRefGoogle ScholarPubMed
Haydel, S.E., Remenih, C.M., & Williams, L.B. (2008). Broadspectum in vitro antibacterial activities of clay minerals against antibiotic-susceptible and anti-biotic resistant bacterial pathogens. Journal of Antimicrobial Chemotherapy, 61, 353–361.CrossRefGoogle Scholar
Heckman, J.R. (2013). Human contact with plants and soils for health and wellbeing. In: Brevik, E.C. & Burgess, L.C. (Eds.). Soils and Human Health (pp. 227–240). Boca Raton, Florida, USA: CRC PressGoogle Scholar
Helmke, M.F. & Losco, R.L. (2013). Soil's influence on water quality and human health. In: E.C. Brevik & L.C. Burgess (Eds.), Soils and Human Health (pp. 155–176). Boca Raton, Florida, USA: CRC Press.Google Scholar
Henley, S.J., Thun, M.J., Chao, A., & Calle, E.E. (2004). Association between exclusive pipe smoking and mortality from cancer and other diseases. Journal of the National Cancer Institute, 96, 853–861.CrossRefGoogle ScholarPubMed
Henry, J.M. & Cring, F.D. (2013). Geophagy: An anthropological perspective. In: E.C. Brevik & L.C. Burgess (Eds.), Soils and Human Health (pp. 179–198) Boca Raton, Florida, USA: CRC PressGoogle Scholar
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, 305–319.CrossRefGoogle Scholar
Hunter, J.M. (1973). Geophagy in Africa and the United States: A culture-nutrition hypothesis. Geographical Review, 63, 170–195.CrossRefGoogle Scholar
Knishinsky, R. (1998). The Clay Cure. Healing Arts Press, Rochester, Vermont, USA. 104 pp.Google Scholar
Londono, S.C., Hartnett, H.E., & Williams, L.B. (2017). Antibacterial activity of aluminum in clays from the Colombian Amazon. Environmental Science and Technology, 51, 2401–2408.CrossRefGoogle ScholarPubMed
Lv, Y., Tao, Y., Yang, Z., Zhao, W., Zhang, M., Wang, Q. (2014). Constraint on selenium bioavailability caused by its geochemical behavior in typical Kaschin–Beck disease areas in Aba, Sichuan Province of China. Science of the Total Environment, 493, 737–749.CrossRefGoogle ScholarPubMed
Lyles, M.B. (2018). Biological, chemical, and environmental hazards of desert dust to military personnel. In: B. De Vivo, H.E. Belkin, & A. Lima (Eds.), Environmental Geochemistry, Second Edition (pp. 467–485). Elsevier, Amsterdam.Google Scholar
Mahaney, W.C., Zippin, J., Milner, M.W., & Sanmugadas, K. (1999). Chemistry, mineralogy and microbiology of termite mound soil eaten by the chimpanzees of the Mahale Mountains, Western Tanzania. Journal of Tropical Ecology, 15, 565–588.CrossRefGoogle Scholar
Mbila, M. (2013). Soil minerals, organisms, and human health: Medicinal uses of soils and soil material. In: E.C. Brevik & L.C. Burgess (Eds.), Soils and Human Health (pp. 199–213). Boca Raton, Florida, USA: CRC Press.Google Scholar
Meldrum, M. & Howden, P. (2002). Crystalline Silica: Variability in fibrogenic potency. Annuals of Occupational Hygiene, 46, 27–30.Google Scholar
Morgan, R. (2013). Soil, heavy metals, and human health. In: E.C. Brevik & L.C. Burgess (Eds.), Soils and Human Health (pp. 59–92). Boca Raton, Florida, USA: CRC Press.Google Scholar
Morman, S.A., & Plumlee, G.S. (2014). Dust and human health. In: P. Knippertz & J.-B.W. Stuut (Eds.), Mineral Dust (pp. 385–409). New York: Springer.CrossRefGoogle Scholar
Morrison, K.D., Misra, R., & Williams, L.B. (2016). Unearthing the antibacterial mechanism of medicinal clay: A geochemical approach to combating antibiotic resistance. Scientific Reports, 6, Article number: 19043.Google Scholar
Perl, D.P. & Moalem, S. (2006). Aluminum, Alzheimer's disease and the geospacial occurrence of similar disorders. In: N. Sahai & M.A.A. Schoonen (editors), Medical Mineralogy and Geochemistry (Vol. 64, pp.115–134). Reviews in Mineralogy and Geochemistry, Mineralogical Society of America and Geochemical Society, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Reinbacher, W.R. (2003). Healing Earths: The Third Leg of Medicine: A History of Minerals in Medicine. 1st Books, 244 pp.Google Scholar
Root-Bernstein, R. & Root-Bernstein, M. (1999). Honey, Mud, Maggots and Other Medical Marvels. Macmillan, London, 279 pp.Google Scholar
Ross, M., Nolan, R.P., Langer, A.M., & Cooper, W.C. (1993). Health effects of mineral dusts other than asbestos. In: Guthrie, G.D. Jr. & Mossman, B.T. (Eds.). Health Effects of Mineral Dusts (Vol. 28, pp. 361–407) Reviews in Mineralogy. Mineralogical Society of America, Chantilly, Virginia, USA.CrossRefGoogle Scholar
Schneider, A. & McCumber, D. (2004). An Air that Kills. Berkley Books, New York, 442 pp.Google Scholar
Selinus, O., Alloway, B., Centeno, J.A., Finkelman, R.B., Fuge, R., Lindh, U., & Smedley, P. (Editors) (2013). Essentials of Medical Geology: Revised Edition. Springer, Dorderecht, The Netherlands, 805 pp.CrossRefGoogle Scholar
Staubach, S. (2005). Clay. Berkley Books, New York, 288 pp.Google Scholar
Tan, J., Zhu, W., Wang, W., Li, R., Hou, S., Wang, D., & Yang, L. (2002). Selenium in soil and endemic diseases in China. Science of The Total Environment, 284, 227–235.CrossRefGoogle ScholarPubMed
Tse, L.A., Dai, J., Chen, M., Liu, Y., Zhang, H., Wong, T.W., Leung, C.C., Kromhout, H., Meijer, E., Liu, S., Wang, F., Yu, I.T-s., Shen, H., & Chen, W. (2015). Prediction models and risk assessment for silicosis using a retrospective cohort study among workers exposed to silica in China. Scientific Reports, 5, Article number: 11059.CrossRefGoogle ScholarPubMed
Turick, C.E., Knox, A.S. & Kuhne, W.W. (2013). Radioactive elements in soil. In: E.C. Brevik & L.C. Burgess (Eds), Soils and Human Health (pp. 137–154). Boca Raton, Florida, USA: CRC Press.Google Scholar
Veniale, F., Bettero, A., Jobstraibizer, P.G., & Setti, M. (2007). Thermal muds: Perspectives and innovations. Applied Clay Science, 36, 141–147.CrossRefGoogle Scholar
Viseras, C., Aguzzi, C., Cerezo, P., & Lopez-Galindo, A. (2007). Uses of clay minerals in semisolid health care and therapeutic products. Applied Clay Science, 36, 37–50.CrossRefGoogle Scholar
Wendlandt, R.F., Harrison, W.J., & Vaughan, J.D. (2007). Surface coatings on quartz grains in bentonites and their relevance to human health. Applied Geochemistry, 22, 2290–2306.CrossRefGoogle Scholar
Williams, L.B. (2017). Geomimicry: Harnessing the antibacterial action of clays. Clay Minerals, 52, 1–24.CrossRefGoogle Scholar
Williams, L. B., Holland, M., Eberl, D. D., Brunet, T., & Brunet de Courrsou, L. (2004). Killer Clasys! Natuaral antibacterial clay minerals. Mineralogical Society Bulletin, 139, 3–8.Google Scholar
Young, S.L. (2011). Craving Earth. Columbia University Press, New York, 228 pp.CrossRefGoogle Scholar