Heavy metals in soils derived from sedimentary rocks of the Gurgueia River watershed, Northeast, Brazil: background values, distribution and ecological risk assessment

• Published in: Environmental geochemistry and health 2024-11, Vol.46 (11), p.438-438, Article 438
• Main Authors: Alves, Paula Nascimento, Cardoso, Kaique Mesquita, Nascimento, Clistenes Williams Araújo do, Barros, Juliana da Silva, Sena, Antonny Francisco Sampaio de, Morais, Pâmalla Graziely Carvalho, Saraiva, Paloma Cunha, Escobar, Maria Eugênia Ortiz, Cunha, Karina Patrícia Vieira da, Boechat, Cácio Luiz
• Format: Article
• Language: English
• Subjects: Anthropogenic factors; Brazil; Cadmium; Chromium; Cluster analysis; Clustering; Cobalt; Crops; Desertification; digestion; Earth and Environmental Science; Ecological risk assessment; Environment; environmental assessment; Environmental Chemistry; Environmental Health; Environmental Monitoring; Environmental policy; Environmental quality; Food contamination; Food quality; Food safety; forests; Fuel combustion; Geochemistry; Geologic Sediments - chemistry; Geostatistics; Heavy metals; indigenous species; Metal concentrations; Metals, Heavy - analysis; Molybdenum; Natural vegetation; Nickel; Original Paper; Pasture; pastures; Perennial crops; Pesticides; Pollution; pollution control; Pollution index; Pollution prevention; Public Health; risk; Risk Assessment; Rivers; Rivers - chemistry; Sedimentary rocks; soil; Soil - chemistry; Soil conservation; Soil Pollutants - analysis; Soil pollution; Soil Science & Conservation; Soil surfaces; Spatial variations; Terrestrial Pollution; Urban development; Urbanization; Vegetation; Water Pollutants, Chemical - analysis; Watersheds; Zinc
• ISSN: 0269-4042; 1573-2983; 1573-2983
• DOI: 10.1007/s10653-024-02216-8

The concentrations of heavy metals (HMs) can be increased by various anthropogenic activities such as mining, fuel combustion, pesticide use, and urban development, which can alter the mechanisms determining their spatial variability in the environment. Determining natural concentrations, monitoring, and assessing potential ecological risks are essential in the management of pollution prevention policies and soil conservation in watersheds. The aim of this study was to determine HMs natural concentrations, establish quality reference values (QRVs), and evaluate pollution indices in a watershed-scale. Composite surface soil samples (n = 115) were collected from areas: native vegetation, pasture, perennial crops, urbanization, planted forest, annual crops, and desertification. The soil samples digestion followed the EPA 3051A, and metals determination in ICP-OES. The data were subjected to the Kruskal–Wallis test, Spearman's correlation, multivariate clustering analysis and. geostatistics. The QRVs established (75th) for the Gurgueia River watershed in descending order were (mg kg −1 ): V (26.16) > Cr (18.06) > Pb (6.24) > Zn (3.86) > Cu (2.66) > Ni (1.45) > Co (0.57) > Mo (0.46) > Cd (0.07). The concentrations of Cd, Co, Cr, Mo, Ni, V, and Zn in types of land and management practices were significantly increased compared to those in natural vegetation. Overall, the watershed falls into the categories of minimal to moderate enrichment, moderate to considerable contamination, and low to moderate potential ecological risk, with Cd presenting elevated values. The percentages of polluted samples ranged from 14.3 to 82.5%, indicating the need for monitoring these areas to ensure environmental quality and food safety. Graphical Abstract