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Quantitative assessment of heavy metals in some tea marketed in Nigeria ——Bioaccumulation of heavy metals in tea

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DOI: 10.4236/health.2010.29162    11,198 Downloads   19,360 Views   Citations


Bioaccumulation of heavy metals in tea marketed in Nigeria was investigated. Four major and most consumed brand of tea were selected for the present study. Both aqueous and dry methods were used. Total contents of metal were determined by digesting 1g of each brand using a mixture (3:1) concentrated nitric acid (NNO3) and hypochlorous acid (HCLO4). The second method involved hot water extract of tea samples. After boiling and filtration, the residue was evaporated to near dryness and digested with concentrated HNO3 and HCLO4 as described above. Results indicate that Zn, Cd, Cu, and Pb were present in lowest concentrations in ascending order for which there were two significant differences between the four sources of samples. The general characteristics of heavy metal concentrations in aqueous extract showed high level of Fe and Mg in a descending order. Going by the correlation study of our result indicates that there is no significant relationship between the two elements of Fe and Mg, though, the numerical values of the two elements varied widely among the samples. These differences may have major impact on human health. However, the beneficial effects of tea are in a fairly narrow concentration range between the essential and the toxic level. In conclusion, the variations in heavy metals content of tea brands may be due to geographical, seasonal changes and the chemical characteristics of the growing regions.

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The authors declare no conflicts of interest.

Cite this paper

Achudume, A. and Owoeye, D. (2010) Quantitative assessment of heavy metals in some tea marketed in Nigeria ——Bioaccumulation of heavy metals in tea. Health, 2, 1097-1100. doi: 10.4236/health.2010.29162.


[1] Soomro, M.T., Zahir, E., Mohiuddin, A., Khan, N. and Naqui, I.I. (2007) Quantitative assessment of metals in local brands of tea in Pakistan. Pakistan Journal of Biological Sciences, 1(2), 1-5.
[2] Ebadi, A.G., Zare, S., Mahdavi, M. and Babaee, M. (2005) Study and measurement of Pb, Cd, Cr, and Zn in green leaf of tea cultivated in Gillan province of Iran. Pakistan Journal of Nutrition, 4(4), 270-272.
[3] Shukla, V., Dhankhar, M., Prakash, J. and Sastry, K.V. (2007) Bioaccumulation of Zn, Cu and Cd in Channa punctatus. Journal of Environmental Biology, 28(2), 395- 397.
[4] Atta, M.B. (1995) Aluminum content in dust black tea leaves and its beverages. Menofiya Journal of Agricultural Research, 20(4), 137-150.
[5] Moghaddam, M.A., Mahvi, A.H., Asgari, A.R., Yonesian, M., Jahed, G.H. and Nazmara, S.H. (2007) Determination of aluminum and zinc in Iranian consumed tea. Environmental Monitoring and Assessment ISSN 0167-6369, Print.
[6] Rachh, P.P., Rachh, M.R., Soniwala, M.M., Joshi, V.D. and Suthar, A.P. (2010) Effect of Gymnema leaf extract on UV-induced damage on Salmonella typhi. Asian Journal of Biological Science, 3(1), 28-33.
[7] Seenivasan, S., Manikandan, N., Muraleedharan, N.N. and Selvasundandan, R. (2007) Heavy metal content of black teas from South India. http//
[8] Fernandez-Caceres, P., Martini, M.J., Pablos, M. and Gonzalez, A.G. (2001) Differention of tea (Camellia sinensis) varieties and their metal content. Journal of Agricultural and Food Chemistry, 49(5), 4775-4779.
[9] Kumar, A., Nair, A.G.C., Reddy, A.V.R. and Garg, A.N. (2005) Availability of essential elements in India and US tea brands. Food Chemistry, 89(2), 441-448.
[10] Gramza, A., Wojciak, R.W., Korezak, J., Hes, M., Wisniewska, J. and Krejpcio, Z. (2005) Influence of the Fe and Cu presence in tea extracts on antioxidant activity. Food Science and Technology, 8(4), 30. http://www.ejpau. media/pl/volume8/issue4/art-30.html
[11] Saud Al-oud, S. (2003) Heavy metal contents in tea and leaves. Pakistan Journal of Biological Sciences, 6(4), 208-212.
[12] Ansari, F., Norbaksh, R. and Daneshmandirani, K. (2007) Determination of heavy metals in Iranian and imported black tea. Iranian Journal of Environmental Health, Science and Engineering, 4(4), 243-248.
[13] Jin, C.W., Du, S.T., Zhang, K. and Lin, X.Y. (2008) Factors determining copper concentration in tea leaves produced at Yuyao County, China. Food Chemistry and Toxicology, 20(6), 1-5.
[14] Tautkus, S., Kazlauskas, R. and Kareiva, A. (2004) Determination of copper in tea leaves by flame atomic absorption spectrometry. CHEIJA, 15(4), 49-52.
[15] Koller, K., Brown, T., Spurgeon, A. and Levy, L. (2004) Recent development in low level exposure and intellectual impairment in children. Environmental Health, 112(9), 987-994.
[16] Han, W.Y., Shi, Y.Z., Ma, L.F. and Ruan, J.Y. (2005) Arsenic, cadium, chromium, cobalt, and copper in different types of Chinese tea. Bulletin of Environmental Contamination and Toxicology, 75(2), 272-277.
[17] Aziz-Al-Rehman, A.M. (1985) Estimation of copper in tea by using two different methods of solution preparation for FAAS. International Journal of Environmental Analytical Chemistry, 22(3), 25.
[18] National Agency for Food and Drug Administration and Control (NAFDAC) (2003) Detention and Estimation of Food Additives, 2(2), 55-59.
[19] Sperling, M.B. and Welz, B. (1999) Atomic absorption spectrophotometer. Wiley-VCH, Weinheim.
[20] Neter, J., Wasserman, W., Kutner, M.H. and Nachtsheim, C.J. (1996) Applied linear statistical models. 4th Edition, McGraw-Hill, Chicago.
[21] Wedepohl, K.H. (2000) The composition of the upper earth’s crust and the natural cycles of selected metals. Metals in raw materials. Natural resources. In: Merian, E., Ed., Metals and their Compounds in the Environment, Part 1, John Wiley and Sons, New York, 3-19.
[22] Hamdaoui, M., Chahed, A., Ellouze-Chabchoud, S., Marouani, N., Abid, Z.B. and HAdhili, A. (2005) Effect of green tea decoction on long-term iron, zinc and selenium status of rats. Annals of Nutrition and Metabolism 49(2), 118-124.
[23] Zhang, M, Zhou, C. and Huang, C. (2006) Relationship between extractable metals in acid soils and metals taken up by tea plants. modele=afiche N& cpsidt=17561212
[24] WHO (1998a) Guidelines for drinking water quality. 2nd Edition, Health Criteria and Other Supporting Information, World Health Organization, Geneva.
[25] WHO (1998b) Guidelines for drinking water quality. 2nd Edition, Health Criteria and Other Supporting Information. World Health Organization, Geneva.
[26] MacLaren, D.S., Burman, D. and Belton, N.R. (1991) Textbook of paediatric nutrition. 3rd Edition, Churchill Livingstone Co., London.

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