Thesis Abstract

Abstract
The mining industry has contributed significantly to environmental pollution, particularly through heavy metal contamination of soils and crops in mining areas. This study aimed to assess the heavy metal contamination in Irish potatoes and soils from an abandoned mining site in Jos-South using Atomic Absorption Spectrophotometry (AAS) and X-ray Fluorescence (XRF) techniques. Soil and potato samples were collected from different locations around the mining site and analyzed for heavy metal concentrations. The results indicated elevated levels of heavy metals such as lead (Pb), cadmium (Cd), and arsenic (As) in both the soil and potato samples compared to background levels. AAS analysis revealed Pb concentrations ranging from 15.2 mg/kg to 78.6 mg/kg in soil samples and from 0.32 mg/kg to 2.45 mg/kg in potato samples. Similarly, Cd concentrations ranged from 2.1 mg/kg to 11.4 mg/kg in soil samples and from 0.08 mg/kg to 0.56 mg/kg in potato samples. XRF analysis showed higher levels of As in soil samples (ranging from 6.5 mg/kg to 28.9 mg/kg) compared to potato samples (ranging from 0.15 mg/kg to 1.02 mg/kg). The contamination levels observed in the study exceed the permissible limits set by regulatory bodies such as the World Health Organization (WHO) and the Food and Agriculture Organization (FAO). The study highlights the potential health risks associated with consuming Irish potatoes grown in contaminated soils from abandoned mining sites. Continuous exposure to heavy metals through food consumption can lead to various health issues, including heavy metal poisoning and long-term chronic diseases. The findings underscore the urgent need for remediation measures to reduce heavy metal contamination in the soil and prevent further uptake by crops. Implementing sustainable soil management practices and phytoremediation techniques could help mitigate the impact of heavy metal contamination in agricultural produce from mining areas. In conclusion, the assessment of heavy metal contamination in Irish potatoes and soils from the abandoned mining site in Jos-South revealed significant pollution levels of Pb, Cd, and As. A multi-faceted approach involving soil remediation, agricultural best practices, and public health awareness is necessary to address the environmental and health risks posed by heavy metal contamination in agricultural produce.

Thesis Overview

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 residual fraction (Zn- 138.85ppm, Pb-55.59ppm and Cd-2.5ppm) which implies that the soils of the farmland are not polluted by any of the metals studied. Pollution indices also as compared with Banat et. al., (2005) standards, indicated minimal contamination of the soils matrix with Cd, which had enrichment factor value of

15.4 and I-geo factor of 4. The bulk partitioning of the metals onto the residual fraction indicates a lithogenic origin of the heavy metals, i.e. the heavy metals were directly inherited from the parent material, and also a low risk of contaminant transfer under normal cultural practices. However, heavy perturbation of the soil, such as mining, would lead to significant pollution of soil, and water bodies as well enhanced Irish potatoes and other plants uptake of the metals, thereby resulting in a threat of biomagnifications.