Assessment of Heavy Metal Contamination in Wetlands Soils Around an Industrial Area Using Combined GIS-Based Pollution Indices and Remote Sensing Techniques

Abstract

Understanding variations of heavy metals and their anthropogenic influence on wetland soils are very imperative and crucial for environmental planning and sustainability. To assess heavy metal contamination in Ibese wetland soils, Nigeria, 30 soil surface (0–20 cm) samples clustered around industrial effluents, were collected and analyzed with atomic absorption spectrophotometer for copper (Cu), zinc (Zn) and cadmium (Cd). Herein, the geo-accumulation (Igeo), and pollution index (PI), coupled with environmental (RS) remote sensing vegetation and water indices were employed as predictor models to assess heavy metals contamination of the area. The vegetation and water indices highlighted an intense decreasing vegetation trend and loss of waterbodies of the area, respectively. The results of the Igeo metals revealed that the wetland soils pollution ranged from uncontaminated to moderately contaminated, except Cd which ranged from moderately to heavy pollution. The PI shows a moderate significant pollution by Cu and Zn, except Cd which recorded considerable contamination. A very significant correlation was found between the metals and the spatial distribution pattern revealed that the contamination is related to the influence of uncontrolled human activities on soil properties like soil pH and organic carbon. The study suggested that adequate attention be directed to alert policymakers and stakeholders toward lessening the anthropogenic sources in the area for future control measures.