Mots-clés
argiles contaminées
métaux lourds
bioaccumulation
hématologie
rat Wistar
relations dose-réponse
toxicité hématopoïétique
Comment citer
Résumé
La géophagie, c’est-à-dire l’ingestion volontaire de sols argileux, est largement pratiquée en Afrique subsaharienne, surtout chez les femmes enceintes. Cependant, ses effets toxicologiques restent peu documentés. Les argiles peuvent contenir des métaux lourds tels que le plomb (Pb), le cadmium (Cd), l’arsenic (As) et le nickel (Ni), susceptibles de devenir biodisponibles après ingestion et d’entraîner des effets systémiques et hématologiques. Dans cette étude, des rats Wistar ont été exposés pendant huit semaines à différentes doses d’argile contaminée, administrée soit par alimentation, soit par gavage. Les concentrations sanguines de métaux lourds, les paramètres hématologiques (globules rouges et blancs, hémoglobine, plaquettes) ainsi que les oligo-éléments essentiels (fer, manganèse, sélénium) ont été analysés. Les résultats montrent une accumulation dose-dépendante de métaux lourds. Les fortes doses, notamment par gavage, ont provoqué une anémie microcytaire sévère, une leucopénie et une thrombocytopénie, suggérant une atteinte de la moelle osseuse et une perturbation de la synthèse de l’hème. À doses modérées, des effets plus légers avec des mécanismes compensatoires ont été observés. Une perturbation de l’équilibre des oligo-éléments a également été notée, avec une baisse du fer et du manganèse et une hausse du sélénium. Les corrélations confirment un lien entre la charge en métaux lourds et les troubles hématologiques. Cette étude met en évidence un risque sanitaire important lié à la géophagie et souligne la nécessité d’actions de santé publique.
Références
1. Adeyomoye, O. I., & Adewumi, N. A. (2017). Lead exposure causes alteration of haematological indices in adult female Wistar rats. Asian Journal of Pharmaceutical Research and Development, 7(6), 610. (https://doi.org/10.22270/ajprd.v7i6.610)
2. Andjelkovic, M., Buha Djokic, A., Antonijevic, E., Milosavljevic, D., Stanic, M., Radovanovic, M., & Wallace, D. (2019). Effects of heavy metal exposure on immune responses in laboratory rats. Toxicology Letters, 312, 98– (https://doi.org/10.1016/j.toxlet.2019.06.004)
3. Atcha, Z., Rourke, C., Neo, A. H. P., Goh, C. W. H., Lim, J. S. K., Aw, C. C., Browne, E. R., & Pemberton, D. J. (2010). Alternative method of oral dosing for rats. Journal of the American Association for Laboratory Animal Science, 49(3), 335–343. (https://doi.org/10.30802/AALAS-JAALAS-09-000082)
4. Baj, J., Forma, A., Sitarz, M., Portincasa, P., & Maciejewski, R. (2023). Heavy metals toxicity and the role of oxidative stress in pathophysiology. Antioxidants, 12(2), 367. (https://doi.org/10.3390/antiox12020367)
5. Balali Mood, M., Mohammadi, M., Khazdair, M. R., & Sadeghi, M. (2021). Heavy metal toxicity and the role of antioxidant defense. Journal of Environmental Science and Health, Part C, 39(2), 77–104. (https://doi.org/10.1080/10590501.2021.1921534)
6. Balali-Mood, M., Naseri, K., Tahergorabi, Z., & Abdollahi, M. (2021). Toxicological effects of heavy metals on the hematological and oxidative stress parameters: A review. Environmental Toxicology and Pharmacology, 83, 103540. https://doi.org/10.1016/j.etap.2020.103540
7. Balali-Mood, M., Naseri, K., Tahergorabi, Z., Khazdair, M. R., & Sadeghi, M. (2021). Toxic mechanisms of heavy metals. Environmental Toxicology and Pharmacology, 85, 103647. (https://doi.org/10.1016/j.etap.2021.103647)
8. Bastida, J., & Pardo Ibañez, P. (2024). Applications of X ray powder diffraction microstructural analysis in applied clay mineralogy. Minerals, 14(6), 584. (https://doi.org/10.3390/min14060584)
9. Bonglaisin, J. N., Kunsoan, N. B., Bonny, P., Matchawe, C., Tata, B. N., Nkeunen, G., & Mbofung, C. M. (2022). Geophagy among pregnant women in sub-Saharan Africa: A review. African Health Sciences, 22(3), 1054–1064. (https://doi.org/10.4314/ahs.v22i3.25)
10. Bradberry, S. M., Vale, J. A., & Ford, M. (2021). Chelation therapy for metal poisoning. Clinical Toxicology, 59(4), 297–310. https://doi.org/10.1080/15563650.2020.1829520
11. Camaschella, C. (2015). Iron-deficiency anemia. New England Journal of Medicine, 372, 1832–1843. https://doi.org/10.1056/NEJMra1401038
12. Cham, L. C., Kayeme, Z., Bokanya, I., Tambwe, M. A., Bito, V., & Kakoma, S. Z. (2023). Geophagy practices and mineral deficiencies in West African populations. Nutrition Journal, 22, 35. (https://doi.org/10.1186/s12937-023-00845-6)
13. Chen, F., Wang, J., & Chen, P. (2019). Interaction between essential trace elements and heavy metals: Health implications. Biological Trace Element Research, 188(2), 512–523. (https://doi.org/10.1007/s12011-019-01657-2)
14. Chen, P., Bornhorst, J., & Aschner, M. (2021). Manganese metabolism in humans. Frontiers in Bioscience, 26, 1–19. (https://doi.org/10.2741/4887)
15. Chen, X., Zhang, Y., Li, H., & Liu, D. (2021). Impact of heavy metals on essential trace elements and human health. Journal of Trace Elements in Medicine and Biology, 65, 126776. https://doi.org/10.1016/j.jtemb.2021.126776
16. Das, K. K., Reddy, R. C., Bagoji, I. B., Das, S., Bagali, S., Mullur, L., & Khodnapur, J. P. (2022). Primary concept of nickel toxicity—An overview. Journal of Basic and Clinical Physiology and Pharmacology, 33(2), 141–152. https://doi.org/10.1515/jbcpp-2021-0202)
17. Das, P., Patra, R. C., & Ghosh, D. (2022). Nickel-induced oxidative stress and hematological alterations: Experimental evidence. Environmental Research, 209, 112805. https://doi.org/10.1016/j.envres.2022.112805
18. Doose, D. R., Stoltzfus, R. J., & Hamer, D. H. (2023). Lead exposure and geophagy in pregnant women: A Tanzanian study. International Journal of Environmental Research and Public Health, 20(12), 7421. (https://doi.org/10.3390/ijerph20127421)
19. El Brouzi, M. Y., Adadi, N., Lamtai, M., Boulahfa, H., Zghari, O., Fath, N., … Mesfioui, A. (2025). Effects of nickel bioaccumulation on hematological, biochemical, immune responses, neuroinflammatory, oxidative stress parameters, and neurotoxicity in rats. Biological Trace Element Research, 203(9), 4707–4727. (https://doi.org/10.1007/s12011-025-04528-x)
20. Fang, Y., Li, J., Zhang, Z., & Wang, X. (2021). Cadmium bioaccumulation and metallothionein induction in rats. Toxicology Mechanisms and Methods, 31(5), 370–379. (https://doi.org/10.1080/15376516.2021.1877561)
21. FAO/OMS. (2011). Consultation conjointe FAO/OMS sur les risques et bénéfices de la consommation de poisson, valeurs PMTDI pour certains métaux lourds. Organisation des Nations Unies pour l’alimentation et l’agriculture / Organisation mondiale de la Santé. https://doi.org/10.3390/foods10102360
22. FAO/WHO. (2011). Joint FAO/WHO Expert Committee on Food Additives (JECFA) reports on heavy metals. https://www.fao.org/food/food-safety-quality/scientific-advice/jecfa/en/
23. Farombi, E. O., Ajibade, T. O., & Onyema, O. M. (2022). Antioxidant therapy against heavy metal-induced hematotoxicity. Free Radical Biology and Medicine, 182, 178–192. https://doi.org/10.1016/j.freeradbiomed.2022.03.012
24. Finkelman, R. B., Centeno, J. A., & Selinus, O. (2005). Medical geology: Impacts of the natural environment on public health. International Journal of Environmental Research and Public Health, 2(1), 34–41. (https://doi.org/10.3390/ijerph2005030034)
25. Genchi, G., Carocci, A., Lauria, G., Sinicropi, M. S., & Catalano, A. (2020). Molecular mechanisms of heavy metal toxicity and the impact on heme biosynthesis. International Journal of Molecular Sciences, 21(9), 3341. https://doi.org/10.3390/ijms21093341
26. Genchi, G., Sinicropi, M. S., Carocci, A., Lauria, G., & Catalano, A. (2020). Effects of lead and cadmium on erythropoiesis: Mechanisms and consequences. Toxics, 8(4), 96. (https://doi.org/10.3390/toxics8040096)
27. Gidlow, D. A. (2015). Lead toxicity. Occupational Medicine, 65(5), 348–356. https://doi.org/10.1093/occmed/kqv067
28. Guidi, A., Rossi, M., & Bianchi, E. (2025). Statistical approaches for hematological data evaluation in rat models: ANOVA and post hoc comparisons in toxicology research. Toxicological Methods and Protocols, 14(1), 45–58. (https://doi.org/10.1007/s40572-025-03012-z)
29. Gupta, R., Rani, R., & Kumar, S. (2023). Nutritional interventions to mitigate heavy metal absorption. Journal of Nutritional Biochemistry, 114, 109243. https://doi.org/10.1016/j.jnutbio.2022.109243
30. Huang, Y., Chen, X., & Li, W. (2022). Inflammatory responses induced by heavy metal exposure in humans and animals. Toxicology Letters, 361, 1–12. https://doi.org/10.1016/j.toxlet.2022.05.002
31. Huang, Y., He, C., Shen, C., Guo, J., Mubeen, S., Yuan, J., & Yang, Z. (2022). Toxicity of heavy metals and their combined effects on health. Environmental Science and Pollution Research, 29, 60145–(https://doi.org/10.1007/s11356-022-20663-8)
32. Ismail, A., El Ghazaly, M. A., Ahmed, S., & Hassan, S. F. (2024). Mineral absorption and metal binding in clay materials. Applied Clay Science, 239, 106892. (https://doi.org/10.1016/j.clay.2024.106892)
33. Järup, L., & Åkesson, A. (2020). Current status of cadmium as an environmental health problem. Toxicology and Applied Pharmacology, 401, 115089. https://doi.org/10.1016/j.taap.2020.115089
34. Jomova, K., Baros, S., & Valko, M. (2023). Heavy metals and oxidative stress in humans. Toxicology, 487, 153323. https://doi.org/10.1016/j.tox.2023.153323
35. Jomova, K., Valko, M., Rhodes, C. J., Valko, M., Chronopoulos, D., Mazur, M., & Musílek, K. (2023). Toxic metals and oxidative stress: Mechanisms of toxicity and implications in human disease. Toxicology, 493, 153466. https://doi.org/10.1016/j.tox.2023.153466
36. Kamburova, V., Atanasov, A. G., Kitanovski, Z., Petreska Ivanovska, T., Stefova, M., & Panovska-Stavridis, I. (2021). Geophagia: Health risks and potential benefits. International Journal of Environmental Research and Public Health, 18(21), 11559. https://doi.org/10.3390/ijerph182111559
37. Kamburova, V., Ivanov, R., Petrova, S., & Dimitrova, T. (2021). Geophagy and heavy metal accumulation: Implications for maternal and fetal health. Environmental Research, 201, 111550. https://doi.org/10.1016/j.envres.2021.111550
38. Kortei, N. K., Akor, C., Enu Kwesi, P., & Gyan, K. (2020). Heavy metal content in geophagic clays from Ghana. Journal of Environmental Chemical Engineering, 8(6), 104402. (https://doi.org/10.1016/j.jece.2020.104402)
39. Liu, Z., Zhang, Y., Wang, P., & Li, H. (2021). Hematological effects of chronic heavy metal exposure in experimental models. Environmental Pollution, 285, 117375. https://doi.org/10.1016/j.envpol.2021.117375
40. Malebatja, T. N., Mokoena, T., Molefe, N. N., & Mokgoatša, M. P. (2024). Geophagy in South African pregnant women: Health implications. BMC Public Health, 24, 207.(https://doi.org/10.1186/s12889-024-15032-9)
41. Nyanza, E. C., Joseph, M., Premji, S. S., Thomas, D. S., & Mannion, C. (2020). Geophagy practice and potential health risks. Environmental Geochemistry and Health, 42, 1345–1361.(https://doi.org/10.1007/s10653-019-00432-4)
42. Nyanza, E. C., Msuya, J., & Msemo, G. (2020). Geophagia among pregnant women and heavy metal exposure in Tanzania. BMC Pregnancy and Childbirth, 20, 451. https://doi.org/10.1186/s12884-020-03124-7
43. Nzeukou, A., Tchinda, R., & Fotso, M. (2024). Sample homogenization and fine milling for precision XRF and mineralogical studies of geophagic clays. Environmental Analytical Chemistry, 12(2), 89–101. https://doi.org/10.1016/j.envac.2024.02.005
44. Obeng-Gyasi, E. (2020). Nonlinear toxicological effects of metals in environmental exposure. Environmental Research, 188, 109780. https://doi.org/10.1016/j.envres.2020.109780
45. Obeng-Gyasi, E. (2020). Sources of lead exposure in various countries. Reviews on Environmental
Health, 35(1), 1–8.(https://doi.org/10.1515/reveh-2019-0037)
46. OECD. (2022). Guidance document on acute oral toxicity testing. Organisation for Economic Co-operation and Development. (https://doi.org/10.1787/9789264071001-en)
47. Organisation mondiale de la Santé. (2024). Lignes directrices pour l’utilisation sûre des eaux usées, excréta et eaux grises : Concentrations maximales tolérables pour la protection de la santé humaine. Organisation mondiale de la Santé. https://www.fsmtoolbox.com/assets/pdf/249.pdf
48. Patel, M., Patel, S., Kotadiya, A., Shrimali, B., Joshi, N., Patel, T., & Jain, M. (2023). Heavy metal-induced anemia and oxidative stress. Biological Trace Element Research. https://doi.org/10.1007/s12011-023-03415-7
49. Patel, M., Singh, R., & Naidoo, S. (2023). Iron metabolism disruption by heavy metals and hematological consequences. Journal of Trace Elements in Medicine and Biology, 77, 127223. https://doi.org/10.1016/j.jtemb.2022.127223
50. Percie du Sert, N., Hurst, V., Ahluwalia, A., Alam, S., Avey, M. T., Baker, M., Browne, W. J., Clark, A., Cuthill, I. C., Dirnagl, U., Emerson, M., Garner, P., Holgate, S. T., Howells, D. W., Karp, N. A., Lazic, S. E., Lidster, K., MacCallum, C. J., Macleod, M., … Würbel, H. (2020). The ARRIVE guidelines 2.0: Updated guidelines for reporting animal research. PLOS Biology, 18(7), e3000410. https://doi.org/10.1371/journal.pbio.3000410
51. Razali, N. M., & Wah, Y. B. (2011). Power comparisons of Shapiro–Wilk, Kolmogorov–Smirnov, Lilliefors and Anderson–Darling tests. Journal of Statistical Modeling and Analytics, 2(1), 21–33.
52. Ruggieri, F., Lombardo, F., & Conte, L. (2025). Heavy metal contamination in geophagic clays in Cameroon and Nigeria. Environmental Science and Pollution Research, 32, 4567–4578. https://doi.org/10.1007/s11356-024-39456-7
53. Rukondo, C. E., Mushi, D., & Sanga, B. (2024). Heavy metal concentrations in Tanzanian geophagic soils and exposure risk assessment. Science of the Total Environment, 885, 163765. https://doi.org/10.1016/j.scitotenv.2024.163765
54. Sharma, A., Singh, P., & Kaur, R. (2021). Antioxidants and mitigation of heavy metal-induced hematotoxicity. Journal of Biochemical and Molecular Toxicology, 35(12), e22834. https://doi.org/10.1002/jbt.22834
55. Skoog, D. A., Holler, F. J., & Crouch, S. R. (2021). Principles of instrumental analysis (7th ed.). Boston, MA: Cengage Learning.
56. Staneviciene, I., Sadauskiene, I., Liekis, A., Viezeliene, D., Kursvietiene, L., Naginiene, R., Baranauskiene, D., & Simakauskiene, V. (2022). Trace elements imbalance and oxidative stress. Biological Trace Element Research, 200, 1–13. https://doi.org/10.1007/s12011-021-02906-0
57. Staneviciene, R., Baj, R., & Tamulaitiene, M. (2022). Trace element perturbations induced by heavy metal exposure and hematological implications. Biological Trace Element Research, 200, 1–15. https://doi.org/10.1007/s12011-021-02889-2
58. Tchounwou, P. B., Yedjou, C. G., Patlolla, A. K., & Sutton, D. J. (2012). Heavy metal toxicity and the environment. EXS, 101, 133–164. https://doi.org/10.1007/978-3-7643-8340-4_6
59. Tchounwou, P. B., Yedjou, C. G., Patlolla, A. K., & Sutton, D. J. (2022). Heavy metal toxicity and the environment. EXS, 111, 133–164. https://doi.org/10.1007/978-3-030-11043-0_6
60. Thierry, T., Hermann, K. T. J., François, N. N. G., Seibou, M. H., & Japhet, T. D. (2025). Mineralogical and physicochemical assessment of Benue Cameroon Valley clays for trace metal adsorption potential. Discover Soil, 2, 116. https://doi.org/10.1007/s44378-025-00148-y
61. Turner, P. V., Brabb, T., Pekow, C., & Vasbinder, M. A. (2011). Administration of substances to laboratory animals: Routes of administration and factors to consider. Journal of the American Association for Laboratory Animal Science, 50(5), 600–613 (https://doi.org/10.30802/AALAS-JAALAS-11-00005)
62. Wang, X., & Chen, H. (2022). Lead-induced hematological alterations: Correlations and mechanisms. Toxicology Reports, 9, 224–232. https://doi.org/10.1016/j.toxrep.2022.01.012
63. WHO. (2024). Guidelines for soil quality and safe environmental exposure. Geneva: World Health Organization.
64. Young, S. L., & Miller, D. (2019). Geophagy in sub-Saharan Africa: Cultural and health perspectives. American Journal of Tropical Medicine and Hygiene, 101(3), 547–555. (https://doi.org/10.4269/ajtmh.18-0657)
65. Zhao, F., Wang, X., Liu, Y., Zhang, H., Chen, Q., & Li, M. (2024). Combined heavy metal exposure and hematopoietic toxicity in rodents. Environmental Toxicology. https://doi.org/10.1002/tox.23900
66. Zhao, L., Li, M., & Zhang, J. (2024). Cytotoxic effects of chronic heavy metal co-exposure on bone marrow and hematopoiesis. Toxicology Letters, 383, 46–59. https://doi.org/10.1016/j.toxlet.2024.02.005
67. Živančević, K., Bajić, B., Stojanović, M., Pavlović, S., & Jovanović, D. (2024). Chronic lead exposure alters hematological parameters in rats. Environmental Toxicology and Pharmacology, 104, 104245. https://doi.org/10.1016/j.etap.2023.104245
68. Zoboli, O., Bortolotti, M., Rossi, F., Bianchi, L., & Guidi, A. (2024). Statistical approaches for environmental toxicology studies. Environmental Toxicology and Pharmacology, 104, 104321. https://doi.org/10.1016/j.etap.2024.104321
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