Assessment of heavy metals bioaccumulation and health risk in crops grown in farmlands around mining sites in Gwana, Alkaleri lga, Bauchi state, Nigeria
Keywords:Bauchi, Bioaccumulation, Heavy Metals, Hazard Quotient, Mining Sites.
Analysis was carried out on farm crops (Guinea corn, Millet and Beans) collected from adjourning farmlands around mining area of Gwana in Alkaleri Local Government Area, Bauchi State. Their heavy metal concentrations were determined and quantified using Atomic Absorption Spectroscopy (AAS). The heavy metal characterization revealed the presences copper, iron, lead, manganese, nickel and zinc in the farm crops. The mean values of the elements that where obtain for copper, iron, lead, manganese, nickel, silver and zinc by AAS are 33.90, 12.00, 71.43, 12.56, 4.40, 0.60 and 101.96 mg/kg, respectively. From the Analysis of variance (ANOVA) used to compare these levels of heavy metals in the crops, it showed that there was a significant difference in their concentration. Exposure assessment and risk characterization of the heavy metals present in the farm crops showed that the mean values of the bioaccumulation coefficient for the elements of copper, iron, lead, manganese, nickel, silver and zinc are1.24, 0.03, 1.68, 0.80,1.64, 0.89 and 1.21 respectively. The estimated daily intake rate for the elements of copper, iron, lead, manganese, nickel and zinc are 1.17 to 1.28 mg/kg, 0.03 to 0.04 mg/kg, 0.06 to 0.011 mg/kg, 1.39 to 1.96 mg/kg, 1.92 to 3.14 mg/kg and 1.18 to 1.26 mg/kg respectively. The hazard quotient for the elements of copper, iron, lead, manganese, nickel and zinc are 0.57â€“1.31, 0.01â€“0.02, 22.95â€“32.50, 0.07â€“0.12, 0.02â€“0.26 and 0.32â€“0.40 respectively. The carcinogenic risk for the elements of lead and nickel are 0.0003â€“0.0011 and 0.0006â€“0.0089 respectively. It is hereby recommended that the farm crop samples from within the catchment areas understudy should be subjected to clinical trials to evaluate the extent of the damage it can cause on body tissues.
 Ademorati CMA (1996). Case studies of bioaccumulation of heavy metals. Environmental chemistry and Toxicology. Foludex press Ltd. Ibadan, Nigeria. pp. 130â€“136.
 Food and Drug Administration, 2001. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Report of the Panel on Micronutrients. National Academy Press, Washington, DC Food and Drug Administration, Dietary supplements, Center for Food Safety and Applied Nutrition.
 Guerra, F., Anderson Ricardo Trevizam2, Takashi Muraoka3*, Nericlenes Chaves Marcante4, Solange Guidolin Canniatti-Brazaca (2012) Heavy metals in vegetables and potential risk for human health. Science Agricola 69 (1) 54-60 https://doi.org/10.1590/S0103-90162012000100008.
 Idzelis, R. L., Budreika A, Vaiskunaite R (2004). Dirvozemio tarsos sunkiaisiais metals Kairiu karinio poligono teritorijoje tyrimai ir vertinimas. Journal of Environmental Engineering and Landscape Management. 12(2):42â€“48.
 Morshdy, A. E. M. A., Rasha M. El Bayomi, Ghada M. Abd El Galil, Abdallah F.A. Mahmoud Heavy (2018) metal concentrations and their risk assessment in marketed slaughtered animals in Sharkia Governorate, Egypt Slov Vet Res. 55 (Suppl 20): 103â€“12
 Nirmal Kumar, J. I., Soni, H. and Kumar, R. N. (2007). Characterization of heavy metals from market vegetables using Inductive Coupled Plasma Analyzer (ICPA). International Journal of Biosciences Reporter 5(1):71â€“76.
 Nivethitha, P., Thnagavel, P., Prince, S. P. M. W. and Subburam, V. (2002). Identification of heavy metal accumulating plants and their use in reclamation of soil contaminated with heavy metals. International Journal of Ecology, Environment and Conservation 8(3):249â€“251.
 Prince, S. P. M. W., Senthilkumar, P. and Subburam, V. (2001). Mulberryâ€“Silkworm food chainâ€“A template to assess heavy metal mobility in terrestrial ecosystems. Environmental Monitoring and Assessment 69:231â€“238 https://doi.org/10.1023/A:1010715606097.
 Song, B., Lei, M., Chen, T., Zheng, Y. M., Xie, Y. F., Li, X.Y. and Gao, D. (2009) Assessing the health risk of heavy metals in vegetables to the general population in Beijing, China. Journal Environmental Science (China) 21:1702â€“1709 https://doi.org/10.1016/S1001-0742(08)62476-6.
 Tsafe, A. I., Hassan, L. G., Sahabi, D. M., Alhassan, Y. and Bala, B. M. (2012). Evaluation of Heavy Metals Uptake and Risk Assessment of Vegetables Grown in Yargalma of Northern Nigeria. Journal of Basic and Applied Science Research 2(12):6708â€“6714.
 United State Environmental Protection Agency, (2011). Risk-based concentration table. United State Environmental Protection Agency, Washington, USA.
 United States Environmental Protection Agency (1989). Risk Assessment Guidance for Superfund Volume I: Human Health Evaluation Manual (Part A). Washington, DC: US Environmental Protection Agency, Office of Emergency and Remedial
 United States Environmental Protection Agency, (2012). Reference dose (RfD): Description and use in health risk assessments, Background Document 1A, Integrated risk information system (IRIS); United States Environmental Protection Agency: Washington, DC,
 Wu, S., Peng, S. P., Zhang, X. X., Wu, D. L., Luo, W., Zhang, T. B., Zhou, S. G., Yang, G. Y., Wan, H. F. and Wu, L. Q. (2015) Levels and health risk assessments of heavy metals in urban soils in Dongguan, China. Journal of Geochemical Explorations 148:71â€“78. https://doi.org/10.1016/j.gexplo.2014.08.009.
 Yi Y, Yang Z. and Zhang S. (2011) Ecological risk assessment of heavy metals in sediment and human health risk assessment of heavy metals in fishes in the middle and lower reaches of the Yangtze River basin. Environ Pollut. 159: 2575â€“85. https://doi.org/10.1016/j.envpol.2011.06.011.
 Zheljazkov, V. D., Craker, L. E., Xing, B. (2006). Effect of Cd, Pb, and Cu on growth and essential contents in dill. Peppermint, and basil. Environmental and Experimental Botany. 58(1â€“3):9â€“16. https://doi.org/10.1016/j.envexpbot.2005.06.008.