Health risk assessment for selected heavy metals in Telfairia occidentalis (fluted pumpkin) leaf retailed in markets within Lokoja metropolis

Ojiego, B.O.; Ogu, G.I; Dantanko, F.; Okolo, J.C.; Audu, K.E.

doi:10.21608/svuijas.2022.154693.1225

Health risk assessment for selected heavy metals in Telfairia occidentalis (fluted pumpkin) leaf retailed in markets within Lokoja metropolis

Document Type : Original Article

Authors

¹ Department of Environmental Biotechnology and Bio-conservation, National Biotechnology Development Agency, 09004 Abuja, Nigeria.

² Department of Microbiology, Federal University Lokoja, 260102 Kogi State, Nigeria.

³ Department of Microbiology, Ahmadu Bello University, Zaria, 810107 Kaduna, Nigeria

10.21608/svuijas.2022.154693.1225

Abstract

This study investigated the levels of selected heavy metals and their potential health risks to consumers within Lokoja metropolis, Kogi State, Nigeria. Fresh pumpkin (Telfairia occidentalis) leaves, obtained from major (International, Old Market, Kpata and Lokongoma) markets within Lokoja, were analyzed for copper (Cu), zinc (Zn), lead (Pb), cadmium (Cd), Nickel (Ni) and manganese (Mn) using standard atomic adsorption spectrophotometer. Daily intake of metals (DIM), target hazard quotient (THQ)/hazard index (HI) and target cancer risk (TCR), were then determined to assess the potential health risks of the metals. Concentrations of Cd (0.18 ± 0.02 and 0.16 ± 0.02 mg/kg), Pb (0.08 ± 0.11 mg/kg and 0.05 ± 0.10 mg/kg) and Zn (1.82 ± 0.04 mg/kg and1.76 ± 0.01 mg/kg) were significantly highest (p < 0.05) in vegetable samples from International and Old Markets when compared with Lokonguma and Kpata Markets which were not significantly different (p˃0.05) from each other. There were insignificant non-carcinogenic risks for the metals except for Cd which could pose risks when the daily ingestion rate is tripled. Target cancer risks were in the increasing order Pb<Cd<Ni<Cu, suggesting moderate cancer risks for Cd and Pb, and high cancer risks Ni and Cu over a life time period of exposure to heavy metal contaminated vegetables within the study location. This study has shown that the heavy metals in T. occidentalis poses subantantilly low health risks when consumed moderately except for Cd, Ni and Cu when the daily consumption rate is significantly increased over a life time period. Hence, intensive awareness campaigns are recommended to enlighten farmers/retailers on safer ways of cultivation/handling of green leafy vegetables.

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