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Assessment of Non-carcinogenic Human Health Risk of some Heavy Metals in Land Snails commonly consumed in Bayelsa State, Nigeria

Author Affiliations

  • 1Department of Chemistry, School of Science, Isaac Jasper Boro College of Education, Sagbama, P.M.B. 74 Yenagoa, Bayelsa State, NIGERIA
  • 2 Department of Pure and Industrial Chemistry, University of Port Harcourt, P.M.B, 5323, Port Harcourt, NIGERIA

Res.J.chem.sci., Volume 5, Issue (10), Pages 61-66, October,18 (2015)


The body burden of Pb, Cu, Zn and Fe in two edible species of land snails (A. achatinaand L. flammea) obtained from the wild in Bayelsa State Nigeria and the non-carcinogenic health risk consequent upon the consumption of these snails was investigated in this study. The concentrations (mg/kg) on dry weight basis of the metals were determined using flame atomic absorption spectrometer, FAAS (GBC Avanta Ver 2.02 model) and found to be (― ± SD)Pb (29.5 ± 4.42), Cu (33.8 ± 6.25), Zn (75.3 ± 4.87) and Fe (2358.3 ± 35.67) for A. achatina and Pb (8.0 ± 082), Cu (23.7 ± 2.62), Zn (138.7 ± 4.49) and Fe (900 ± 303.56) for L. flammea. The target hazard quotients (THQs) and hazard index (HI) for evaluating the non-carcinogenic health risk was obtained from the individual and combined heavy metals due to dietary intake. THQ for the individual metals in A. achatina andL. flammea are in the decreasing order of Fe > Cu > Zn > Pb with risk value of 1.39, 0.34, 0.10, 0.00 and 0.53, 0.24, 0.19 and 0.00 respectively. Fe is the major contributor of the risk value which accounted for 55 - 75% of the THQs. The hazard index (HI) value obtained for A. achatina and L. flemmea were 1.83 and 0.96 respectively. The HI values indicates the presence of potential adverse health risk through the consumption of these two species of land snails. Therefore, moderate consumption of A. achatina and L. flemmea may be advisable considering the bio-accumulative nature of metals and to avoid human health risks to consumers in the future.


  1. Fagbuaro O, Oso J.A., Edward J.B. and Ogunleye R.F., Nutritional status of four species of giant land snails in Nigeria, J Zhejiang Univ Sci B., 7(9), 686–689 (2006)
  2. Cimino G. and Carisi C., Acute Toxicity of Heavy Metals to Aerobic Digestion of Waste Cheese, Wheyi Bio Waste,33, 201-202 (1990)
  3. Nuenberg K.J., Fresh water Molluscs as Sentinel Organisms of Heavy Metal Accumulation in Fresh Water Ecosystems, J. Environ. Pollut., 16, 23-26 (1984)
  4. Bryan G.W. and Langstone W.J., Bioavailability, Accumulation and Effects of Heavy Metals in Sediments with Special Reference to United State Kingdom Estuaries: A Review Environ Pollut, 76(2), 89-131 (1992)
  5. Kiffney P.M. and Cement W.H., Bioaccumulation of Heavy Metals by Benthic Invertebrates at the Arkansas River Colorado Environ, Toxicol Chem, 12(8), 1507-1517 (1993)
  6. Coughtrey P.J. and Martin M.H., The Distribution of Pb, Zn and Cu within the Pulmonate Mollusc Helixaspersa Oecologia, 23, 315-322 (1976)
  7. Boening D.W., An Evaluation of Bivalves as Biomonitors of Heavy Metals Pollution in Marine Waters, Environ Monit Assess, 55, 459-470 (1997)
  8. Kumar B. and Mukherjee D.P., Assessment of Human Health Risk for Arsenic, Copper, Nickel, Mercury and Zinc in Fish Collected from Tropical Wet Lands in India, Advances in life Science and Technology, 2, 13–24 (2011)
  9. WHO (World Health Organization), Toxicological Evaluation of Certain Food Additives: Copper, Zinc, WHO Food Additive Series N0, 17 (1982)
  10. USEPA (Environmental Protection Agency), Guidance for Assessing Chemical Contaminant Data for Use in Fish Advisories, Vol. 1. Fish Sampling and Analysis 3rdEdition Office of Science and Technology of Water, Washington, DC EPA 823 – B – 00 – 007: 1 – 20, (2000)
  11. USEPA, Risk Assessment Guidance for Superfund: Vol III Part A. Process for Conducting Probalistic Risk Assessment EPA, 540-R-02-002 OSWER 92857-45PB2002 963302, (2001)
  12. USEPA, Human Health Risk Assessment, Available at http://www.epa.gov/riskk/health-risk.htm Retrived. 11/05/2013, (2012)
  13. Amirah M.N., Afiza A.S., Faizai W.I.W., Nurliyana M.H and Laili S., Human Health Risk Assessment of Contamination through Consumption of fish, Journal of Environ. Pollution and Human Health,1(1), 1–5 (2013)
  14. Liao C.M. and Ling M.P., Assessment of Human Health Risks for Arsenic Bioaccumulation in Tilapia (Oreochromis Mossambicus) and Large Scale Mullet (Liza Macrolepis) from black foot disease Area in Taiwan, Arch. Environ. Toxicol.,45, 264–272 (2003)
  15. Osakwe J.O, Adowei P. and Horsefall M.Jr., Heavy Metals Body Burden and Evaluation of Human Health Risks in African Catfish (Clarias Gariepinus) from Imo River, Nigeria, Acta Chim Pharma Indica, 4(2), 78–89 (2014)
  16. Ijeomah H.M., Edet D.I., Oruh E.K. and Ijeomah A.U., Assessment of Heavy Metals in Tissue of Selected Non-vertebrate Wildlife Species in oil Polluted Sited of Delta State, Nigeria, Agricultural and Biology Journal of North America, 6(2), 63–73 (2015)
  17. Jennings G.D., Sneed R.E. and Clair M.B. St., Metals in Drinking Water. Published by: North Carolina Cooperation Extension Service Publication N0: AG – 473 – 1 Electronic Version 3, (1996)
  18. Res. J. Chem. Sci. International Science Congress Association 66Captive–Reared Alligator (Alligator Mississipiensis) possible Contribution to Reproductive Failure, Toxicology and Pharmacology, 142, 30–35 (2006)
  19. Reena Singh, Neetu Gantam, Anurage Mishra and Rajiv Gupta, Heavy Metals and Living Systems, An over view, India Journal of Pharmacology, 43(3), 246–253 (2011)
  20. Horsfall M. Jnr., Chemistry and Heavy Metas are Janus: Faced, University of Port Harcourt Inaugural Lecture Series N0, 81, 20–22 (2011)
  21. Kuhnlein H.V. and Chan H.M., Environmental and Contaminants in Traditional Food Systems of Northern Indigenous People, Ann. Rev. Nutr.,20, 595 – 626 (2000)
  22. Chien L.C., Hung Chong K.Y., Yeh C.Y., Meng P.J., Shieh M.J. and Han B.C., Daily Intake of TBT, Cu, Zn, Cd and AS for Fisherman in Taiwan, The Science of the Total Environment, 285, 177–185 (2002)
  23. Hallenback W.H., Quantitative Risk Assessment for Environmental and Occupational Health, Lewis, Chelsea, MI, (1993)
  24. WHO, 41st Report of the Joint FAO/WHO. Expert Committee on Food Additives, WHO Technical Report Series. N0. 837. Geneva, (1993)
  25. WHO, Joint FAO/WHO. Expert Committee on Food Additive. In: Summary and Conclusions 53rd Meeting, Rome, 1-10, (1999)
  26. WHO, Joint FAO/WHO. Expert Committee on Food Additive. In Summary and Conclusion, 61st Meeting: methyl Mercury, http://www.who.int/pcs/Jecfa/summary 61.Pdf, (2003)
  27. FEPA, Guidelines and Standards for Environmental Pollution Control in Nigeria, 238, (2003)