ASSESSMENT OF HEAVY METAL CONTAMINATION IN IRISH POTATOES AND SOILS FROM AN ABANDONED MINING SITE IN JOS-SOUTH, USING AAS AND XRF TECHNIQUES.

ABSTRACT

This study was undertaken to assay the elemental concentration in some Irish potatoes and soils from farmlands in an ex-mining area at Dahwol-vwana village, Jos-south L.G.A, Plateau state, Nigeria. The total heavy metal concentrations (for Irish potato and soil samples) were obtained using Atomic Absorption Spectrometer. It was observed from the soil sample concentration values gotten at the end of the AAS analysis (Pb, ranges from 0.0445-3.9343ppm; Cd, from 0.0086- 0.1200ppm and Zn, from 0.0751-39.0302ppm) are higher than the concentration values obtained from control area (Pb- 0.0088ppm, Cd-0.0029ppm and Zn-0.0101ppm), but lesser than the international threshold values (EU:- Pb-300ppm, Cd-3.0ppm and Zn-300ppm. USA: - Pb- 300ppm, Cd-3.0ppm and Zn-250ppm. UK:- Pb-70ppm, Cd-1.4ppm and Zn-200ppm). While that of Irish potatoes: - Pb, ranges from 0.0741-1.5042ppm; Cd, from 0.0081-0.0931ppm and Zn, from 0.1038-88.0503ppm). A modified sequential extraction procedure of Tessier et. al., (1979) was used in separating the total metal concentrations into four operationally defined fractions (exchangeable and carbonate, Fe and Mn oxides, organic matter, and residual fractions). Where it was discovered that the bulk of metals were partitioned to the