Heavy metal concentration in fluted pumpkin (Telfaira occidentals) and health risk assessment in Obio/Okpor, Rivers State, Nigeria
Date
2021-06
Authors
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Publisher
Federal University of Technology, Owerri
Abstract
Heavy metals are non biodegradables and are inimical to human health. This research work was therefore carried out to establish heavy metal concentration in fluted pumpkin (Telfairia occidentalis) in Obio/Akpor, Rivers state Southern Nigeria. Vegetable and soil samples were collected from ten different locations, taken to the laboratory and analyzed using standard methods. Six heavy metals (Pb, Cr, Cd, Zn, Cu and Fe) discovered in the vegetables were analyzed using an Atomic Absorption Spectrophotometer (AAS). Consequently, human health risk levels associated with the consumption of these metals were also determined. The mean heavy metals concentration in the vegetable ranged as follows: Zn(7.56-36.77mg/kg), Fe(261.42-416.06mg/kg), Pb(1.00-2.01mg/kg), Cd(0.35- 0.55mg/kg), Cu(4.62mg/kg) and Cr(1.49mg/kg), The concentrations of all metals were generally below the permissible limits of WHO/FAO in vegetables except for Pb, Cd and Cr in some locations. However, statistical analysis of levels of the studied metals in T. occidentalis showed significant differences (p>0.05). The heavy metal concentration was in the order: Fe>Zn>Pb>Cu>Cr>Cd. In terms of location, Iriebe showed the highest heavy metal concentration; followed by Oginigba and Rumuodara, which was the control showed the least. To assess the health risk of the inhabitants of Obio/Akpor due to heavy metal intake from T. occidentalis consumption, the target hazard quotient (THQ), daily intake of metals (DIM), health risk index (HRI) and hazard index (HI) were calculated. The daily intake of Cu (0.393) and Zn (1.978) were lower than the recommended daily intake level of metals and the tolerable upper intake level (UL). But the DIM of Pb (0.128), Cd (0.038) and Fe (27.488) exceeded the recommended daily intake level however, fall within the tolerable upper intake level. Cr (0.127) was lower than the recommended oral reference dose (RfD) of 1.5mg/kg. The THQ of all heavy metals in this study was less than 1; therefore, it does not pose health risk concern. However, The HRI and HI values show that the population may be at risk of heavy metal contamination.
Since T. occidentalis consumption is only one out of the many popular vegetables planted in this area, if other vegetable consumption as well as other routes of heavy metals exposure is considered, the potential health risks for the inhabitants might be higher than in this study. Therefore, there is need for continuous monitoring of heavy metals contamination because of its toxicity effect.
Description
This thesis is for the award of the Master of Science (MSc.) in Environmental Management (Pollution Control Option)
Keywords
Heavy metals, T. occidentals, daily intake of metals (DIM), health risk index, target hazard quotient (THQ), health risk index (HRI), hazard (Index), Department of Environmental Management
Citation
Udofia, H. S. (2021). Heavy metal concentration in fluted pumpkin (Telfaira occidentals) and health risk assessment in Obio/Okpor, Rivers State, Nigeria (Unpublished Master's Thesis). Federal University of Technology, Owerri, Nigeria