@article{Tyopine_Obalum_Igwe_Okoye_2022, title={Spatial distribution and relative enrichment of some upper-group trace elements in rhizosphere of highly anthropized and rapidly developing tropical environment}, volume={49}, url={https://eqa.unibo.it/article/view/14554}, DOI={10.6092/issn.2281-4485/14554}, abstractNote={Most upper-group (Groups 13-17) trace elements, some of which are micronutrients, are toxic. Soil concentrations, distribution and relative enrichment of ten of these elements were studied at Ikwo, southeastern Nigeria, representing largely disturbed and rapidly evolving humid tropical ecosystems. Sampling was from the 0-50-cm soil layer of fallow lands in the four cardinal zones (with marked agricultural/mining activities) and a reference central zone. Elemental concentrations were determined using Inductively Coupled Plasma Atomic Emission Spectroscopy. Enrichment factor was calculated as the ratio of each element to that of Fe (a reference element) in the soil. The central and north zones had the highest and lowest concentrations (21.00-10.75, 1.83-0.93, 10.90-5.58, 4.05-2.05, 4.97-2.54, 2.20-1.12, 17.75-9.09, 26.74-13.69, 4.41-2.26 and 1.89-0.96 mg kg–1, respectively for Se, As, B, Al, Si, S, Sn, Sb, I and Br), implying that mining/agricultural activities rather reduced their accumulation in the rhizosphere. Enrichment factors indicated extreme-to-significant levels in the soils for five of the elements (Si > Sb > B > Al > Se) and moderate-to-insignificant levels for the rest (Br > Sn > I > S > As). However, the elements showed similar distribution/enrichment patterns across the five zones including the reference zone. These patterns together suggest greater dependence of the enrichment levels of especially those with extreme-to-significant enrichments on the relative abundance of the elements in the earth’s crust than on the mining/agricultural activities in the agroecosystem. Thus, these activities at their current modes and intensities in the humid tropics apparently may not constitute any ecological risks.}, number={1}, journal={EQA - International Journal of Environmental Quality}, author={Tyopine, Andrew and Obalum, Sunday and Igwe, Charles and Okoye, Chukwuma}, year={2022}, month={Jan.}, pages={19–33} }