Milk is one of the very important nutrients of human diet. The presence of toxic elements in milk may threaten the public health. This study reports the levels of Cadmium (Cd), Cobalt (Co) and Lead (Pb) in raw cow’s milk collected from different areas of Zanzibar Island during March - May 2016. The samples of raw milk were analyzed by Thermo Scientific-Atomic Absorption Spectrophotometer for quantitative determination of the metals in the matrix. The concentration of Co in this study ranged from ND at Mwanakwerekwe (MK1 and MK2) to a maximum of 0.004 mg/L at Mshelishelini (MS5) and Fuoni (F5) sites with mean concentration of 0.020 ± 0.003 mg/L for all sites. Concentration of Pb ranged between 0.05 - 0.51 mg/L at Fuoni (F7) and Mwanakwerekwe (MK1) respectively, with mean concentration of 0.263 ± 0.031 mg/L for all sites. However, Cd was only detected in one sample collected at Fuoni (F3) with a concentration of 0.001 mg/L. The results revealed that cow’s milk is contaminated with toxic metals, particularly Pb which exceeded the WHO maximum permissible level of 0.02 mg/L. The study furthermore sheds light on possible consequences to public health. It is recommended that, stakeholders especially in Zanzibar such as Zanzibar Food and Drug Authorities (ZFDA) and Zanzibar Bureau of Standards (ZBS) as well as researchers, use the findings of this study for policy making, future study plans, formulation of technical strategies to control milk contamination, risk assessment and develop new alternative methods to measure milk contamination even at a low detection limit for the sake of the consumers’ welfare before posing any serious effects to their health.
References
[1]
Abdulkhaliq, A., Swaileh, K.M., Hussein, R.M. and Matani, M. (2012) Levels of Metals (Cd, Pb, Cu and Fe) in Cow’s Milk, Dairy Products and Hen’s Eggs from the West Bank, Palestine. International Food Research Journal, 19, 1089-1094.
[2]
Enb, A., Abu Donia, M.A., Abd-Rabou, N.S., Abou-Arab, A.A.K. and El-Senaity, M.H. (2009) Chemical Composition of Raw Milk and Heavy Metals Behavior during Processing of Milk Products. Global Veterinaria, 3, 268-275.
[3]
Ogabiela, E.E., Udiba, U.U., Adesina, O.B., Hammuel, C., Ade-Ajayi, F.A., Yebpella, G.G. and Abdullahi, M. (2011) Assessment of Metal Levels in Fresh Milk from Cows Grazed around Challawa Industrial Estate of Kano, Nigeria. Journal of Basic and Applied Scientific Research, 1, 533-538.
[4]
Jamal, M.K., Kazi, T.G., Arain, M.B., Afridi, H.I., Jalbani, N. and Memon, A.R. (2007) Heavy Metal Contents of Vegetables Grown in Soil, Irrigated with Mixtures of Wastewater and Sewage Sludge in Pakistan, Using Ultrasonic-Assisted Pseudo-Digestion. Journal of Agronomy and Crop Science, 193, 218-228. https://doi.org/10.1111/j.1439-037X.2007.00261.x
[5]
Liobet, J.M., Falco, G., Casas, C., Teixido, A. and Domingo, J.L. (2003) Concentrations of Arsenic, Cadmium, Mercury, and Lead in Common Foods and Estimated Daily Intake by Children, Adolescents, Adults, and Seniors of Catalonia, Spain. Journal of Agricultural and Food Chemistry, 51, 838-842. https://doi.org/10.1021/jf020734q
[6]
Qin, L.-Q., Wang, X.-P., Li, W., Tong, X. and Tong, W.-J. (2009) The Minerals and Heavy Metals in Cow’s Milk from China and Japan. Journal of Health Science, 555, 300-305. https://doi.org/10.1248/jhs.55.300
[7]
Neal, A.P. and Guilarte, T.R. (2013) Meschnisms of Lead and Manganese Neurotoxicity. Toxicology Research, 2, 99-114. https://doi.org/10.1039/c2tx20064c
[8]
Smith, R.M., Leach, R.M., Muller, R.D., Jr.Griel, L.C. and Baker, D.E. (1991) Effect of Long Term Dietary Cadmium Chloride on Tissue, Milk, and Urine Mineral Concentrations of Lactating Dairy Cows. Journal of Animal Science, 66, 4088-4096. https://doi.org/10.2527/1991.69104088x
[9]
Triphathi, R.M., Raghunath, R., Sastry, V.N. and Krishnamoorthy, T.M. (1999) Daily Intake of Heavy Metals by Infants through Milk and Milk Products. Science of the Total Environment, 227, 229-235. https://doi.org/10.1016/S0048-9697(99)00018-2
[10]
Ataro, Z., Geremew, A. and Urgessa, F. (2018) Occupational Health Risk of Working in Garages: Comparative Study on Blood Pressure and Hematological Parameters between Garage Workers and Haramaya University Community, Harar, Eastern Ethiopia. Risk Management and Healthcare Policy, 11, 35-44. https://doi.org/10.2147/RMHP.S154611
[11]
Salma, I., Maenhaut, W., Dubtsov, S., Papp, E.Z. and Zaray, G. (2000) Impact of Phase out of Leaded Gasoline on the Air Quality in Budapest. Microchemical Journal, 67, 127-133. https://doi.org/10.1016/S0026-265X(00)00108-9
[12]
Ahmad, W.M.S. (2002) Studies on Heavy Metal Pollution Farm in Relation to Production Performance. Ph.D. Thesis, Zagazig University, Zagazig.
[13]
Sujka, M., Pankiewicz, U., Kowalski, R., Mazurek, A., Ślepecka, K. and Góral, M. (2019) Determination of the Content of Pb, Cd, Cu, Zn in Dairy Products from Various Regions of Poland. Open Chemistry, 17, 694-702. https://doi.org/10.1515/chem-2019-0072
[14]
Kunusa, W.R., Thomas, N., Silaban, D.P., Iyabu, H. and Taupik, M. (2020) Concentration of Pb, Sn and Fe Metals on Milk Products and Canned Fish in Gorontalo City. IOP Conference Series: Earth and Environmental Science, 589, Article ID: 012033. https://doi.org/10.1088/1755-1315/589/1/012033
[15]
European Food Safety Authority (EFSA) (2009) Scientific Opinion of the Panel on Contaminants in the Food Chain on a Request from the European Commission on Cadmium in Food. The EFSA Journal, 980, 1-139. https://doi.org/10.2903/j.efsa.2009.980
[16]
EFSA Panel on Contaminants in the Food Chain (CONTAM) (2010) Scientific Opinion on Lead in Food. The EFSA Journal, 8, p 151. “ https://doi:10.2903/j.efsa.2010.1570
[17]
Pilarczyk, R., Wójcik, J., Czerniak, P., Sablik, P., Pilarczyk, B. and Tomza-Marciniak, A. (2013) Concentrations of Toxic Heavy Metals and Trace Elements in Raw Milk of Simmental and Holstein-Friesian Cows from Organic Farm. Environmental Monitoring and Assessment, 185, 8383-8392. https://doi.org/10.1007/s10661-013-3180-9
[18]
Belete, T., Hussen, A. and Rao, V.M. (2014) Determination of Concentrations of Selected Heavy Metals in Cow’s Milk: Borena Zone, Ethiopia. Journal of Health Science, 4, 105-112.
[19]
Elatrash, S. and Atoweir, N. (2014) Determination of Lead and Cadmium in Raw Cow’s Milk by Graphite Furnace Atomic Absorption Spectroscopy. International Journal of Chemical Science, 12, 92-100.
[20]
Codex Alimentarius Commission. (2019) General Standard for Contaminants and Toxins in Food and Feed.CXS, 193-1995.
[21]
Abdus-Salam, N. (2009) Assessment of Heavy Metals Pollution in Dumpsites in Ilorin Metropolis. Ethopian Journal of Environment Studies and Management, 2, 51-55. https://doi.org/10.4314/ejesm.v2i2.45926
[22]
Moges, A. (2014) Determination of Levels of Some Heavy Metals (Pb, Cr and Cd) in Three Commercially Available Brands of Milk Powder Found in Harar Town, Eastern Hararge, Ethiopia. MSc. Thesis, Haramaya University, Harar.
[23]
Rosen, C.J. (2002) Lead in the Home Garden and Urban Soil Environment. St. Paul, MN: University of Minnesota Extension Service. FO-02543-B.
[24]
Cerkvenik, V., Doganoc, D.Z. and Jan, J. (20000) Evidence of Some Trace Elements, Organochlorine Pesticides and PCB in Slovenian Cow’s Milk. Food Technology and Biotechnology, 38, 155-160.
[25]
Pilsbacher, L. and Grubhofer, F. (2002) Mercury, Lead and Cadmium in Austrian Raw Milk—A Comparison to Earlier Analyses from Foreign Countries, Wien. Wiener Tierärztliche Monatsschrift-Veterinary Medicine Austria, 89, 249-253.
[26]
Licata, P., Trombetta, D., Cristina, M., Giofre, F., Martino, D. and Calo, M. (2004) Levels of “Toxic” and “Essential” Metals in Samples of Bovine Milk from Various Dairy Farms in Calabria, Italy. Environment International, 30, 1-6. https://doi.org/10.1016/S0160-4120(03)00139-9
[27]
Boltea, F., Bretan, L., Ketney, O. and Moldovan, C. (2008) Heavy Metals Concentration in Milk from the Baia Mare Depression. Journal of Agroalimentary Processes and Technologies, 14, 485-491.
[28]
Simsek, O., Simsek, R., Gultekin, O. and Kurultay, S. (2000) The Effect of Environmental Pollution on the Heavy Metal Content of Raw Milk. Food / Nahrung, 44, 360-371. https://doi.org/10.1002/1521-3803(20001001)44:5<360::AID-FOOD360>3.0.CO;2-G
[29]
Najarnezhad, V. and Akbarabadi, M. (2013) Heavy Metals in Raw Cow and Ewe Milk From North-East Iran. Food Additives & Contaminants: Part B, 6, 158-162. https://doi.org/10.1080/19393210.2013.777799
[30]
Castro-González, N.P., Calderón-Sánchez, F., Castro de Jesús, J., Moreno-Rojas, R., Tamariz-Flores, J.V., Pérez-Sato, M. and Soní-Guillermo, E. (2018) Heavy Metals in Cow’s Milk and Cheese Produced in Areas Irrigated with Waste Water in Puebla, Mexico. Food Additives & Contaminants: Part B, 11, 33-36. https://doi.org/10.1080/19393210.2017.1397060
[31]
Parween, R., Shahid, S., Yasmeen, K. and Ara, D. (2016) Evaluation of Environmental Impact on Heavy Metal Load in Cattle Milk. Polish Journal of Environmental Studies, 25, 1161-1166. https://doi.org/10.15244/pjoes/61231
[32]
Khan, N., Jeong, S., Hwang, M., Kim, J.S., Choi, S.H., Nho, E.Y., Choi, J.Y., Park, K.S. and Kim, K.S. (2014) Analysis of Minor and Trace Elements in Milk and Yogurts by Inductively Coupled Plasma-Mass Spectrometry (ICP-MS). Food Chemistry, 147, 220-224. https://doi.org/10.1016/j.foodchem.2013.09.147
[33]
Kulek de Andrade, C., Klack de Brito, P.M., dos Anjos, V.E. and Quináia S.P. (2018) Determination of Cu, Cd, Pb and Cr in Yogurt by Slurry Sampling Electrothermal Atomic Absorption Spectrometry: A Case Study for Brazilian Yogurt. Food Chemistry, 240, 268-274. https://doi.org/10.1016/j.foodchem.2017.07.111
[34]
Castellani, V., Fusi, A. and Sala, S. (2017) Consumer Footprint Basket of Products indicator on Food. JCR Technical Reports. Publications Office of the European Union, Luxembourg.
[35]
Chary, N.S., Kamala, C.T., Samuel, D. and Raj, S. (2008) Assessing Risk of Heavy Metals from Consuming Food Grown on Sewage Irrigated Soils and Food Chain Transfer. Ecotoxicology and Environmental Safety, 69, 513-524. https://doi.org/10.1016/j.ecoenv.2007.04.013
[36]
Patočka, J. and Černý, K. (2003) Inorganic Lead Toxicology. Acta Medica, 46, 65-72. https://doi.org/10.14712/18059694.2019.8
[37]
National Research Council (NRC) (2001) Nutrient Requirements of Dairy Cattle 7th Revised Edition, National Academy of Sciences, Washington DC
[38]
Henry, P.R. (1995) Cobalt Bioavailability. In: Ammerman, C.B., Baker, D.H. and Lewis, A.J., Eds., Bioavailability of Nutrients for Animals, Academic Press, Cambridge, 119-126. https://doi.org/10.1016/B978-012056250-3/50033-0
[39]
Thornton, I. (1992) Sources and Pathways of Cadmium in the Environment. IARC Scientific Publications, 118, 149-162.
[40]
Rahimi, E. (2013) Lead and Cadmium Concentrations in Goat, Cow, Sheep, and Buffalo Milks from Different Regions of Iran. Food Chemistry, 136, 389-391. https://doi.org/10.1016/j.foodchem.2012.09.016
[41]
Farid, S.M., Enani, M.A. and Wajdi, S.A. (2004) Determination of Trace Elements in Cow’s Milk in Saudi Arabia. Journal of King Abdulaziz University Engineering Sciences, 15, 131-140. https://doi.org/10.4197/Eng.15-2.9
[42]
Wuana, R.A. and Okieimen, F.E. (2011) Heavy Metals in Contaminated Soils: A Review of Sources, Chemistry, Risks and Best Available Strategies for Remediation. International Scholarly Research Notices, 2011, Article ID: 402647. https://doi.org/10.5402/2011/402647
[43]
Adekeni, M.B., John, A.M., Angela, O. and Anuoluwapo, A. (2023) Determination of Toxic and Trace Heavy Metals in the Soil of Two Different Dumpsites: A Case Study of Ojota and Oko Filling Dumpsites, Lagos State. Science Journal of Chemistry, 11, 51-55.
