Evaluation of Heavy Metal Contamination in Mining Ponds and Farms Around Kuru Jantar Mining Sites, Jos South LGA, Plateau State, Nigeria

Abstract

The use of abandoned mining wells and ponds for dry season irrigation farming may lead to elevated levels 
of heavy metals in the soils and plants. This study therefore, evaluated levels of some heavy metals in farms 
and mining ponds around Kuru Jantar mining sites, Jos South, Plateau State, Nigeria. The levels of heavy 
metals in the soil samples were determined using XRF whereas the levels in water samples were determined 
using AAS. The results revealed the average concentrations of Zn, Cu, Ni, Cr, Mn, Fe, Ti, and V to be 
54.26±6.65 mg/kg, 239.61±0.44 mg/kg, 74.65±6.80 mg/kg, 325.00±29.63 mg/kg, 1048.58±355.17 mg/kg, 
59108.23±651.42 mg/kg, 851.29.23±21.35 mg/kg, 322.12±28.01 mg/kg respectively. The levels of heavy 
metals were above the FEPA recommended permissible limit in agricultural soil, Zn (300 mg/kg; Cu (100 
mg/kg); Ni (50 mg/kg); Cr (250 mg/kg); Mn (800 mg/kg); Fe (4000 mg/kg) and V (100 mg/kg) except Zn 
which was below. The average concentrations of the heavy metals in the farms decreased in the order Fe 
> Mn > Ti > Cr > V > Cu > Ni > Zn. The levels of the heavy metals in the vegetables were generally within 
the recommended safe limits in vegetables for Mn (500 mg/kg); Cu (73.00 mg/kg) except Pb, Zn and Fe 
which were above their safe limits of Pb (0.30mg/kg; Fe (425.50mg/kg) and Zn (60 mg/kg). Similarly, the 
results of the heavy metals concentration in the water samples were higher than the recommended WHO 
maximum values Pb (0.02mg/L); Cr (0.05mg/L); Mn (0.40mg/L); Cu (2.00 mg/L); Ni (0.02 mg/L) and Cd
(0.03mg/L) in water. The average concentrations of the heavy metals in water samples decreased in the 
order Zn > Cu > Ni > Cd > Mn > Cr > Ni > Pb. Generally, the concentrations of the heavy metals in the 
soil and water were higher than their respective controls. Thus, it follows that the illegal mining played a 
part in the increased values of these heavy metals in the environment. Therefore, the need to keep a check 
on the illegal mining activities is recommended to reduce health risk and the degree of heavy metals 
pollution.