Prediction of trace element dynamics at the Lite-Bala site in the Democratic Republic of Congo (DRC)

Abstract

The transfer of trace elements from the soil to plants is determined by the physico-chemical characteristics of the soil, the nature and  content of the trace elements and the duration of exposure. The aim of this study is to determine the physico-chemical characteristics of  the soils at Lite-Bala that influence this transfer. Random sampling and analysis of physico-chemical parameters were carried out.  Statistics were used to visualise the results and identify the key variables. The study showed that soils and sediments were more acidic  (4.55 ± 0.35 - 5.86 ± 0.16) and oxidising (319.19 ± 8.18 – 387.58 ± 20.78 mV) than surface and pore waters (pH 6.43 ± 0.32 - 6.72 ± 0.49 and  Eh ≤ 280 mV). Organic carbon levels were low (< 1.5%). Soil and sediment clay contents ranged from around 35 - 42% and 7 - 17%  respectively. Statistically, the total inertia rate of 91.4 indicates with certainty that pH, oxidising power, clay and sand content regulate the  transfer of trace elements from the soil to plants. There is a proven risk to human health and the environment at the Lite-Bala site.  Monitoring and quantification of trace elements at the site is necessary to protect human health and the environment.