Assessment of Contamination, Health Risk and Bio-Accessibility of Harmful Elements (HEs) i

Abstract

The research investigated the contamination, health risk and bio-accessibility of ten Harmful Elements (HEs) within the soils of small-scale gold mining and processing sites in Minna, North-Central Nigeria. Geochemical analysis of 33 soil samples was carried out using Inductively Coupled Mass Spectrophotometry (ICPMS) method. Harmful elements in the soil which include Cu, Pb, Zn, Ni, Fe,As, Mn, U, Cr and Cd varied in ppm from 12.24 – 1387.66, 9.21- 22595, 20.78-1068.05, 3.49-76.40, 13797.20 – 106242.50, 1.0 – 3659.04, 257.21-1850.36, 0.93 – 10.01, 8.65 – 121.57 and 0.03-11.83 respectively. The concentrations of HEs were above upper crustal continental values (UCC) and China standards recommended for agricultural soils in most of the samples. The contamination degree and potential ecological risk indices ranged between 5.1 to 2224.8 and 34.44 to 35110.34 which indicated low to very high degree of contamination and low to very high potential risk posed by different HEs in soil respectively. Cd, Cr andAs also posed a low to moderate carcinogenic risk in the soil. Pb and As contributed >70% to the health risk and highest exposure routes was from ingestion. The results of bioaccessible fraction (BAF), as the proportion of HEs which are bioaccessible in the stomach or gastrointestinal tract from the sample matrix showed that Mn, Cu, Zn, Pb and Cd were within very high biocaccessibilty factor, Arsenic showed high biocaccessibilty factor, Cr, Ni, and U showed intermediate biocaccessibilty factor while Fe showed low bioaccessibility factor. Bioaccessibility hazard quotient (BHQ) for most HEs were also above safe value of 1. This showed that all the HEs investigated are bioaccessible and could cause both carcinogenic and non-carcinogenic health risks to residents with a higher risk in children than in adults.

Publication Info:

Author: Odukoya, A.M.1, Adedayo, T.O.1, Watts, M.J.2,Banjo, Y.3, Ane

Volume: 59

Issue: September

Published By: Journal of Mining and Geology Vol. 59(2) 2023. pp. 199 - 216, 2023-09-01