Accepted Paper



Investigation of Estimated Daily Intake of Toxic Metals and Potential Health Risks in Oreochromis noliticus (Tilapia Fish)

Kayode Idowu Ogungbemi1, Imade Yolanda Nsa2, Latifat Ronke Owoade3
1Department of Physics, Faculty of Science, University of Lagos, Nigeria
2Department of Microbiology, Faculty of Science, University of Lagos, Nigeria
3National Institute of Radiation Protection and Research, University of Ibadan, Oyo State Nigeria
Abstract. Oreochromis noliticus (Tilapia fish) is one of the major sources of protein and its readily available in all the markets, Agboyi river is one of the major outlet of Tilapia fish in the southwest Nigeria this was the motivation for this study. Pb, Cr, Mn, Cd, Zn and Ni were identified from Oreochromis noliticus (Tilapia fish). Objectives: This study aimed to quantify the level of heavy metals and determine the health risk index (HRI) level using estimated daily intake (EDI) of Oreochromis noliticus in samples collected. Methodology: Oreochromis noliticus samples were collected (samples D1 to D3) from Agboyi river a fresh water river, and dried then the edible tissues were separated from the other parts of the fish, this was then digested for a Perkin-Elmer model 306 Atomic Absorption spectrophotometer (AAS) for the analysis to ascertain the levels of concentration of the metals identified in the samples. Results: From the samples D1 to D8, for Pb concentrations is the highest in sample D8 with the value of 7.32?0.65 mg/kg and lowest in the sample D6 with the value of 0.02?0.33 mg/kg. The Ni concentration is highest in sample D5 with value 2.72?0.03 mg/kg, lowest in sample D6, D8 and not detectable (ND) in sample D1. Zn concentration is highest in sample D3 with the mean concentration of 62.99?0.05 mg/kg and lowest in sample D6 with a value of 0.74?0.14 mg/kg. Cr mean concentration in D3 and D6 are 8.51?0.54 mg/kg and 0.02?0.63 mg/kg respectively the highest and the lowest in all the samples. Whereas, Mn mean concentration are 9.51?0.42 mg/kg and 0.73?0.07 mg/kg in sample D4 and D7 respectively and this implies that sample D4 has the highest while sample D7 has the lowest values of Mn. Cd has the highest mean concentration values in D1 and the lowest in D6 with values of 5.76?0.66 mg/kg and 0.01?0.68 mg/kg respectively. These values where used to compute the EDI for both children and adults using each sample per heavy metal identified. The EDI for the children is within the range of 0.012-0.638 mg/kgBw/day and for the adults within the range of 0.002-0.193 mg/kgBw/day. The health risk index (HRI) greater than unity in samples D1 and D3, whereas in other samples is less than unity. The targeted cancer risk (TCR) was estimated in Pb and Ni obtained results were less than USEPA 2010 recommended values. Conclusion: From the obtained results, the HRI obtained from the samples collected did not exceed the standard guideline values, so therefore; the estimated hazard index (HI) suggests that it safe to consume fish from Agboyi River.

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