The Temporal Response of Trace and Toxic Elements to Landscape Indices of Doce River Basin, Brazil after the Fundão Dam Collapse

Abstract

Trace and potentially toxic elements were correlated with landscape indices in the Doce River Basin in Brazil after the Fundão dam collapse. Surface water samples were submitted to the Environmental Protection Agency (EPA3051A) methodology, and figures of merit were evaluated. The certified reference material of trace elements in water was used to check the accuracy. Statistical analyses were applied to identify the factors influencing element concentrations. The predictor variables were land use, soil types, meteorological factors, and longitudinal distances. The total concentration of arsenic, chromium, manganese, nickel, phosphorus, and lead, and dissolved aluminum, copper, and iron exceeded the maximum limits established by Brazilian Resolution, mainly in the upper Doce River during the rainy season. Rainfall was the predictor variable that most affected the response, influenced by dissolved copper and iron. The highest concentration of dissolved aluminum and total phosphorus were obtained during the dry season. Correlation analysis revealed a fair correlation (>0.47-0.67, p < 0.05) among all elements in surface water with soil type, forestry, and forest. The main sources of pollution were total manganese and dissolved aluminum and iron, originating from mining activities. The study emphasizes the impact of the dam collapse during the 2022-2023 period and stresses the importance of improving sewage treatment in the area.