Comparative Assessment of Heavy Metal Concentrations in Soya Beans, White Beans, and Red Beans Sold in Gamawa Local Government Area, Bauchi State, Nigeria

This work quantified and compared four heavy metals — cadmium (Cd), chromium (Cr), copper (Cu), and zinc (Zn) — across soya beans (Glycine max), white beans, and red beans (Phaseolus vulgaris) marketed in Gamawa Local Government Area, Bauchi State, Nigeria. A total of twenty-seven samples, drawn from three wards (Kafiromi, Alagarno, and Tumbi), were subjected to tri-acid digestion (HNO₃: HClO₄:H₂SO₄, 5:1:1) prior to elemental analysis using Microwave Plasma Atomic Emission Spectrophotometry (MP-AES 4200). Of the three legume types, soya beans carried the greatest burden of all four metals (Cd 0.12, Cr 0.85, Cu 8.45, Zn 25.60 mg kg⁻¹), with red beans intermediate and white beans lowest. Against FAO/WHO permissible limits, only cadmium in soya beans and red beans surpassed the 0.10 mg kg⁻¹ ceiling; chromium, copper, and zinc stayed within acceptable bounds throughout. Metal loads varied by location, with Kafiromi ward showing the greatest contamination and Alagarno the least. Applying the Daily Intake of Metals (DIM), Hazard Quotient (HQ), and Hazard Index (HI) framework, all computed HI values (0.443–0.513) fell beneath the threshold of 1, pointing to no meaningful non-carcinogenic risk at present consumption levels. Overall, the three bean types appear largely safe to eat, though the cadmium overshoot in soya beans and red beans justifies ongoing surveillance of local soils, irrigation sources, and food crops, together with better agronomic practices and food-safety outreach.

Heavy metals; Soya beans; White beans; Red beans; Bioaccumulation; Hazard index; Food safety.

1. Almas, L. O., & Bender, O. (1980). Nutrition for nurses (2nd ed.). Tropical Health Series, London Group Limited, pp. 91–92. [Google Scholar] [Crossref]

2. Amin, E. K. (2019). Facilitative mechanisms of lead as a carcinogen. Mutation Research, 533, 12–133. [Google Scholar] [Crossref]

3. Antonious, T., & Konchhar, B. (2009). Heavy metal toxicology. The Tortoise Shell Service of Health Newsletter, 34–35. [Google Scholar] [Crossref]

4. Barau, Y. A. (2018). Concentrations of Cu and Zn in some fruits and vegetables commonly available in North Central Zone of Nigeria. Electronic Journal of Environmental, Agricultural and Food Chemistry, 6(6), 2150–2154. [Google Scholar] [Crossref]

5. Boyd, T. C., & Rajakaruna, H. E. (2013). Nutritive value and effect of balancing on trypsin and chymotrypsin inhibitor activities of selected leafy vegetables. Plant Foods and Human Nutrition, 54, 271–283. [Google Scholar] [Crossref]

6. Cichy, E., Serin, M., Leblebici, Z., & Aksoy, A. (2015). Heavy metals accumulation in some vegetables and soils in Istanbul. Ekoloji, 21(82), 1–8. [Google Scholar] [Crossref]

7. Clarke, M. G. M., Snow, E. T., & Tanaka, A. (2011). Arsenic and heavy metal contamination of vegetables grown in Santa village, Bangladesh. Science of the Total Environment, 308(3), 83–96. [Google Scholar] [Crossref]

8. Col, J. J. (1999). Processing tropical crops: A technological approach. MacMillan Publishers, London, pp. 170–172, 226–246. [Google Scholar] [Crossref]

9. D'mello, I. E. (2019). Physicochemical studies on oils from five selected Nigerian plant seeds. Pakistan Journal of Nutrition, 6(6), 75–78. [Google Scholar] [Crossref]

10. Delbari, R. K., Agrawal, M., & Kulkarni. (2013). Heavy metals contamination of soil and vegetables in suburban areas of Varanasi, India. Ecotoxicology and Environmental Safety, 66, 258–266. [Google Scholar] [Crossref]

11. Dheri, L. H. (2004). Food chemistry (2nd ed.). CBI Publishers, New Delhi, pp. 1–385. [Google Scholar] [Crossref]

12. Efremova, P. C. R. M., Krishnakumar, N., & Izosimova, M. (2018). Bioaccumulation of lead and the influence of chelating agent in Catla catla fingerlings. Environmental Chemistry Letters, 7, 51–54. [Google Scholar] [Crossref]

13. FAO/WHO. (2012). Permissible limits of heavy metals in soil and plants. World Health Organization, Geneva, Switzerland, p. 940. [Google Scholar] [Crossref]

14. Fergusson, P. (2020). Regional health issues related to hazardous waste. Central European Journal of Public Health, 2(Suppl.), 16–20. [Google Scholar] [Crossref]

15. IARC. (2019). Official methods of analysis of the International Agency for Research on Cancer (17th ed.). Association of International Agency Research on Cancer, pp. 96–105. [Google Scholar] [Crossref]

16. IARC. (2021). Official methods and recommended practices of the American Oil Chemists' Society. IARC Press, Washington, DC, pp. 69–84. [Google Scholar] [Crossref]

17. Kabata-Pendias, K. (2011). Wild vegetables used by the Sambas in the Usambara Mountains, Tanzania. Annales Botanici Fennici, 37, 57–67. [Google Scholar] [Crossref]

18. Ma, A. (2018). Environmental biotechnology (2nd ed.). Oxford University Press, Oxford, UK, p. 32. [Google Scholar] [Crossref]

19. Maigari, M. D. (2017). Proximate analysis and determination of some heavy metals in Moringa oleifera and Telefaria occidentalis (M.Sc. thesis). Department of Pure and Industrial Chemistry, Bayero University Kano, pp. 22–26. [Google Scholar] [Crossref]

20. Manzoor, A. N., & Atif. (2018). Physico-chemical, microbiological and sensory stability of chemically preserved mango pulp. Pakistan Journal of Botany, p. 28. [Google Scholar] [Crossref]

21. McLaughlin, S. R., Jeffe, D. M., & Skinner, M. A. (2016). Case report of metallic mercury injury. Paediatric Emergency Care, 13(2), 113–116. [Google Scholar] [Crossref]

22. Morales, S. S., Adefemi, O. S., Oyakilome, I. G., Ajibulu, K. E., & Asaolu, M. F. (2020). Proximate and mineral composition of Nigerian leafy vegetables. Journal of Food Research, 1(3), 214–218. [Google Scholar] [Crossref]

23. Mutune, K. J., Fanuel, K., George, O., & Paul, O. (2012). Assessment of heavy metal concentrations in urban grown vegetables in Thika Town, Kenya. African Journal of Food Science, 6(3), 41–46. [Google Scholar] [Crossref]

24. Olatunde, M., Mathew, B. B., Shah, M. S., & Gowda, K. R. S. (2020). Biosorption of few heavy metal ions using agricultural waste. Journal of Environmental Pollution and Human Health, 2(1), 1–6. [Google Scholar] [Crossref]

25. Opaluwa, R., & Chang, A. C. (2012). Trace elements and urban gardens. University of California Co-operative Extension (UCCE) Newsletter, 3, 14–19. [Google Scholar] [Crossref]

26. Papanikolaou, F. A., Carlson, R. W., & Rolf, G. L. (1999). The effect of heavy metals on plant environmental pollution. Environmental Pollution, 7, 241–246. [Google Scholar] [Crossref]

27. Prasad, S. (2008). Biology work. Cambridge University Press, 3(2), 47–54. [Google Scholar] [Crossref]

28. Rascio, Y., & Navari-Izzo, I. (2011). Towards an integrated understanding of heavy metals in the European built environment. Journal of Urban Forestry and Urban Greening, 8(2), 65–75. [Google Scholar] [Crossref]

29. Robins, J., & McNeal. (2019). Definition of heavy metals and their meaning in biological systems. Journal of Manufacturing Science and Engineering, 132(6), 060–101. [Google Scholar] [Crossref]

30. Säumel, N., Affonso, C. G., & Lauro, A. R. (2020). Cemeteries heavy metal concentration analysis of soil and contamination risk for the surrounding resident population. International Journal of Engineering Research and Application, 6(6), 30–35. [Google Scholar] [Crossref]

31. Shaheen, M., Habadi, I., Bandar, & Alamar, K. (2019). Assessing the level of health literacy among adult visitors in the primary care settings of functional guard health affairs, Jeddah, Saudi Arabia. Journal of Health. [Google Scholar] [Crossref]

32. Singh, M. S., & Rahman, M. U. (2019). Heavy metal contamination through industrial effluent to irrigation water and soil in Korangi area of Karachi (Pakistan). Journal of Agriculture and Biology, 7, 646–648. [Google Scholar] [Crossref]

33. Su, A., Sridhar, R. K., Agrawal, M., & Marshall, F. M. (2007). Risk assessment of heavy metal toxicity through contaminated vegetables from wastewater-irrigated area of Varanasi, India. International Society for Tropical Ecology, 51, 375–387. [Google Scholar] [Crossref]

34. Surudii, L. E., & Khanna, K. (2020). Trace elements in tropical Asian muddy soils. Soil Science, Plants and Nutrition, 29(4), 439–452. [Google Scholar] [Crossref]

35. Teshome, K., & Emire, M. (2012). Hazard waste in the Slovak Republic. National Report, Central European Journal of Public Health, 3(2), 43–48. [Google Scholar] [Crossref]

36. Toth, N., Oniye, S. J., Balarabe, M. L., & Auta, J. (2017). Concentration of Fe, Cu, Cr, Zn, and Pb in Makera Drain, Kaduna, Nigeria. Chemical Class Journal, 4(2), 69–73. [Google Scholar] [Crossref]

37. Untawale, E. A. G., McGinnis, J. A., Jaffe, O., & Kakade. (1969). Environmental Science and Technology, 25, 89–96. [Google Scholar] [Crossref]

38. USEPA. (2006, 2016). Reference dose and risk assessment guidance for heavy metals. United States Environmental Protection Agency. [Google Scholar] [Crossref]

39. Wilson, W., & Pyatt, I. (2007). Environmental analytical chemistry. Blackie Academic and Professional, Chapman and Hall, London, pp. 56–60. [Google Scholar] [Crossref]

40. Xiong, S., Cao, Zheng, Y. M., Huang, Y. Z., & Zhu, Y. S. (2018). Health risk of heavy metals in contaminated soil and food crops irrigated with wastewater in Beiji [Google Scholar] [Crossref]

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