Determination of Heavy Metal Concentrations on some Selected Herbal Medicinal Preparations Marketed in Kano State, Nigeria


  • Zigau, Z. A. Department of Biological Science, Faculty of Science Bauchi State University Gadau, Bauchi State Nigeria
  • Aliyu, B. S. Department of Plant Biology, Faculty of Life Science, Bayero University Kano, Kano State Nigeria.
  • Abubakar, U. S. National Biotechnology Development Agency, (NABDA) Abuja, Nigeria
  • Bello, A. A. Department of Biology, faculty of Natural and Applied science, Nigerian Army University Biu, Borno State Nigeria
  • Yakasai, M. A. Department of Biology, Aliko Dangote University of Science and technology,Wudil Kano State Nigeria
  • Sanusi, H. Department of Plant science and biotechnology, Federal University Dutsinma, Katsina State Nigeria



Traditional medicine, heavy metals, permissible limits, contamination


Study’s Novelty/Excerpt

  • This study assesses heavy metal concentrations in traditional medicinal herbs consumed in Kano State, Nigeria, providing critical insights into their relative safety and potential health risks.
  • By analyzing ten powdered herbal samples using Atomic Absorption Spectrometry, the research identifies concerning levels of lead, chromium, cadmium, and mercury, with lead concentrations in one sample exceeding the WHO's safety limits.
  • The findings highlight significant variability in heavy metal content among different herbs, underscoring the need for stringent quality control and regulatory measures to ensure consumer safety.

Full Abstract

Herbs are extensively consumed in Nigeria, for their medicinal properties and availability. This study aimed at determining the concentration of heavy metals residues in some selected traditional medicinal herbs consumed in Kano State, Nigeria. This is to assess their relative safety and potential health risks to local inhabitants based on the World Health Organization standard limit. A total of ten (10) powdered samples of medicinal preparations were purchased from local markets in Kano metropolis and analyzed for the presence of lead, chromium, cadmium, and mercury contents. The samples underwent digestion, and heavy metal concentrations were determined using Atomic Absorption Spectrometry (AAS). The metals found to be present varied in different concentrations in the herbal samples. The presence of heavy metal ranges as follows: 0.6-6.5mg/kg for chromium, 3.10-22.10mg/kg for lead, 0.08-0.60mg/kg for cadmium, and 0.09-0.30mg/kg for mercury. However, mercury content was not detected in some samples. The study's findings conclude that the lead (Pb) values were found to be the highest in concentration, exceeding the W.H.O limits in sample J, which is used as a remedy for cough. This indicates that the sample is highly contaminated compared to others. Mercury was not detected in four of the samples, and when present, it was below the limits set by the World Health Organization, making all the samples free from mercury contamination.


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Abdullahi H, (2019) “Analysis and Evaluation of the Effect of Heavy Metals in Fruits And vegetables’’ International Journal of Trend in Scientific Research and Develp Ment Development (IJTSRD), Volume: 3, Issue: 2, Available Online: e-ISSN: 2456 – 6470.

Abdullahi, M., Abubakar, U.,S, and Safiyanu I. (2019). Phytochemical analysis and accumulation Phytochemical analysis and accumulation of heavy metals in some common medicinal Plants. Journal of Pharmacogn Phytochem 2019; 8(3): 2692-2696p.

Akinloye, O., Arowojulu, A. O., Shittu, O. B., and Anetor, J. I. (2016). Cadmium concentration Cadmium Toxicity: a Possible Cause of Male Infertility in Nigeria. Reproductive Biology, 6:7-30.

Alaribe, C. S., Oladipupo, A. R., Musah, A. A. and Coker, H. A. B. (2018). Investigation of Sel-cted Metallic Impurities in Antimalarial Herbal Decoctions Agbo Iba Collected from Four Locations in Lagos State, Nigeria. UNILAG Journal of Medicine, Science and Technology, 6(1): 45-56.

Alpang, K., and Arun, S. (2015). Investigation of heavy metals in frequently used medicinal plants collected from diverse locations in India. Journal of alternative medicine 4 (1) pp 33-36.

Bala, M., Shehu R. A. & Lawal, M (2018) “Determination of the levels of some heavy Metals in water collected from two pollution- prone irrigation areas around kano metr opolis” Bayero Journal of Pure and Applied Sciences, 1(1):36 – 38 Vol. 1 Number 1 .

Chen , J., Yei, Y., Ran, M., Li, Q., Ruan, Z., and Jin, N. (2020). Inhibition of tyrosinase by mercury chloride spectroscopic and docking studies. Journal of pharmacology 11 (2)23-25.

Chizhti, K.A., Khan, F.A., and Hassan S.M. (2021) . Estimation of heavy metals in seeds of blueand white capitulums of silybum marianum grown in various districts of Pakistan. Journal of basic applied Science, 7(1), 45-49.

Daniel, E. S., Musa, J. J., Akos, M. P., Yerima, I. Y., Dada, P.O., Jibril, I. and Manta, I. H. (2016) “Assessment of heavy metal pollution in some Nigerians Soil: A review 37 37th Annual conference and Annual general meeting in Minna

Felagha I, Ogbolosingha A.J (2018) “Assessment of heavy metals concentration in selected selected foods sold in markets within port-Harcourt city, Nigeria” Open Access Jour rnal of Science, Volume 2 Issue 4.

Goulart, M., Batoreu, M. C., Rodrigues, A. S., Laires, A. and Rueff, J. (2015). Chromium in herbLipoperoxidation Products and Thiolantioxidants in Chromium Exposed Workers. Mutagenesis, 20(5):311-315.

Li, S., M. Fang, Y., Ning, and Y. X. Wu. (2016). “Heavy metals in Chinese therapeutic foodsand herbs,” Journal of the Chemical Society of Pakistan, vol. 34, no. 5, pp. 1091–1095.

Muhammad, U.K, Riffat, N.M, Said M, Faizan U & Abdul Q, (2020): “Health Risk Assessment of Consumption of Heavy Metals in Market Food Crops from Sialkotand Gujranwala Districts, Pakistan, Human and Ecological Risk Assessment, An International Journal, DOI: 10.1080/0807039.2014.913445

Muwanga, A., (2017).Environmental impact of copper and cadmiummining at Kilembe, UgandaA geochemical investigation of heavy metal pollution of drainage waters, stream, sediments and soils in the Kilembe valley in relation to mine waste disposal. Ph.D. dissertation. UniversitatBraunschweig, Germany.

Odoh, R. and Ajiboye, O. (2019). Emmanuel Quality Assessment of Some Selected Herbal drugsMedicinal Products Consumed In Wukari, Taraba. Journal of Acta Scientific Microbiology, 2(9): 28-36.

Rausan, Z., Anwar, H., Oboye, U., and Nilufar, N. (2019). Microbial and heavy metal contamination of Antidiabetic herbal preparations formulated in Bagaledash. Journal of Alternative Medicine. 3 (1) pp 13-15.

Saad, B. H., Azaizeh, H.G., Abu-Hijleh, and Saim, O. (2020). “Safety of traditional Arab herbal medicine,” Evidence-Based journal of Complementary and Alternative Medicine, vol. 3, no. 4, pp. 433–439, 2006.

Sanda Y.S (2015) “Assessment of heavy metal contamination in irish potatoes and soils from an abandoned mining site in jos-south, using AAS and XRF” Physics M.Scthesis Submitted to ABU postgraduate school.

Sathiavelu, R., Street, R.A., Kulkarni, M.G., Stirk, W.A., Southway, C., Van Staden, J. (2019).Variation in heavy metals and microelements in South African medicinal plants obtained from street markets. Food Additives & Contaminants. Part A: Chemistry, Analysis, Control, Exposure & Risk Assessment 25, 953–960.

Street, R.A., Stirk, W.A., and Van Staden, J. (2020). South African traditional medicinal plant trade—challenges in regulating quality, safety and efficacy. Journal of Ethnopharmacology 119:705–710.

Sulyman Y.I ,Abdulrazak S, Oniwapele Y.A & Ahmad A (2015), “Concentration of heavy metals in some selected cereals sourced within Kaduna state, Nigeria” IOSR Journal of Environmental Science, Toxicology and Food Technology (IOSR-JESTFT) e-ISSN:2319-2402. p-ISSN: 2319-2399. Volume 9, Issue 10 Ver. II, pp. 17-19, DOI: 10.9790/2402-091021719

Umar, A., Mohammed, Y., Garba, S. and Faruruwa, M. D. (2016) Quantitative Determination ofHeavy Metals in some Commonly Consumed Herbal Medicines in Kano State, Nigeria. Journal of Scientific and Engineering Research, 3(2):39-46.

World Health Organization, WHO. (2017). Guidelines for Assessing Quality of Herbal Medicines with Reference to Contaminants and Residues, WHO Press, Geneva, Switzerland.

W.H.O. (2019). WHO guidelines for assessing quality of herbal medicines with reference to contaminants and residues. s14878e.pdf (Accessed 21/02/2014). 543–548.

World Health Organization. Guidelines for Assessing Quality of Herbal Medicines with Reference to Contaminant and Residue. Geneva, Switzerland

Wang, G.Y., 2021. Effects of Se and Zn supplementation on the antagonism against Pb and Cd in vegetables. Journal of Environment and International science. 30, 167–17.

Singh, R., Gautam, N,. Mishra, A.,and Gupta, R. (2021). “Heavy metals and living systems“ an overview,” Indian Journal of Pharmacology, vol. 43, no. 3, pp. 246–253, 2011.

Yusuf, I. N., Samali, A., Mohammed, M. I., and Ibrahim, M. B. (2020). Analysis of Heavy Metal Concentration in Kano Herbal Preparations for Major Disease Conditions. Journal of Chemical research, 8(2): 22-28.




How to Cite

Zigau, Z. A., Aliyu, B. S., Abubakar, U. S., Bello, A. A., Yakasai, M. A., & Sanusi, H. (2024). Determination of Heavy Metal Concentrations on some Selected Herbal Medicinal Preparations Marketed in Kano State, Nigeria. UMYU Journal of Microbiology Research (UJMR), 207–213.