Assessment of Heavy Metal Concentrations in Pumpkin Grown along River Benue, Makurdi Local Government Area of Benue State, Nigeria

Abstract

This study aimed at detecting and assessing the concentrations of heavy metals in Pumpkin irrigated using surface and groundwater sources grown along the banks of River Benue, Makurdi, Nigeria. Eight heavy metals were detected to include cadmium, chromium, cobalt, copper, iron, manganese, lead and zinc. The mean concentration of heavy metals in pumpkin irrigated with surface water obtained from Fiidi, Wurukum, new garage and Wadata areas of Makurdi was determined using triplicate values obtained from heavy metal analysis. The results show the mean concentrations of heavy metals to include Cd (2.07 ± 0.1), Cr (2.07 ± 0.1), Co (0.803 ± 0.01), Cu (3.14 ± 0.1), Mn (2.51 ± 0.02), Pb (1.05 ± 0.05) and Zn (9.03 ± 0.03). Fiidi had Cd (1.02 ± 0.03), Cr (2.24 ± 0.04), Co (0.417 ± 0.02), Cu (2.61 ± 0.01), Fe (1.03 ± 0.02), Pb (1.22 ± 0.02) and Zn (6.81 ± 0.001). Wurukum had mean concentration of Cd Cr, Co, Cu, Fe, Mn, Pb, and Zn to be 0.920 ± 0.03, 1.61 ± 0,02, 0.410 ± 0.02, 2.42 ± 0.02, 1.02 ± 0.03, 1.22 ± 0.02, 1.41 ± 0.01 and 8.54 ± 0.04 for the heavy metals respectively. On the other hand, pumpkin irrigated with surface water around New garage had a mean concentration of 0.710 ± 0.03, 2.13 ± 0.03, 0.410 ± 0.01, 2.90 ± 0.01, 1.11 ± 0.02, 2.03 ± 0.06, 0.527 ± 0.03, 3.11 ± 0.01, 1.22 ± 0.07, 1.81 ± 0.02, 1.22 ± 0.03 and 6.83 ± 0.06 for Cd, Cr, Co, Cu, Fe, Mn, Pb and Zinc respectively. The mean concentrations of heavy metals in pumpkin irrigated with groundwater were Manganese was highest in Zua (4.64 ± 0.03) and cobalt (0.410 ± 0.02) was lowest, Fiidi had Zinc (9.01 ±0.01) as the highest whereas cobalt had 0.517 ± 0.02 as the lowest mean concentration. The new garage had 7.85 ± 0.06 and 0.517 ± 0.02 whereas Wadata had 8.24 ± 0.2 and 0.4 ± 0.02 for zinc and cobalt as the highest and lowest mean concentration respectively. The presence of the heavy metals in pumpkin planted in the locations studied did not vary significantly since all the heavy metals detected were present in all the samples studied at P> 0.05.