1
|
Skorupa ALA, Bispo FHA, Assunção SA, Oliveira JR, Lima FRD, Teixeira MB, Guilherme LRG, Scolforo JRS, Zinn YL, Marques JJ. Spatial distribution of Pb and Zn in soils under native vegetation in Southeast Brazil. ENVIRONMENTAL GEOCHEMISTRY AND HEALTH 2024; 46:84. [PMID: 38367079 DOI: 10.1007/s10653-024-01859-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Accepted: 01/04/2024] [Indexed: 02/19/2024]
Abstract
Heavy metals can play an important biological role as micronutrients but also as potentially toxic elements (PTEs). Understanding the natural concentrations of PTEs-Pb and Zn included-in soils allows for the identification and monitoring of contaminated areas and their role in environmental risk assessment. In this study, we aim to determine semi-total or natural and available concentrations of Pb and Zn in topsoils (0-20 cm depth) from 337 samples under native vegetation in the State of Minas Gerais, Brazil. Additionally, we sought to interpret the spatial geochemical variability using geostatistical techniques and quality reference values for these elements in soils were established. The semi-total concentrations were determined by flame and graphite furnace atomic absorption after microwave-assisted nitric acid digestion method. The available concentrations were extracted using the Mehlich-I extractor and determined by atomic absorption spectrometer. Spatial variability was modeled using semivariance estimators: Matheron's classic, Cressie and Hawkins' robust, and Cressie median estimators, the last two being less sensitive to extreme values. This allowed the construction of digital maps through kriging of semi-total Pb and Zn contents using the median estimator, as well as other soil properties by the robust estimator. The dominance of acidic pH and low CEC values reflects highly weathered low-fertility soils. Semi-total Pb contents ranged from 2.1 to 278 mg kg-1 (median: 9.35 mg kg-1) whereas semi-total Zn contents ranged from 2.7 to 495 mg kg-1 (median: 7.7 mg kg-1). The available Pb contents ranged from 0.1 to 6.92 mg kg-1 (median: 0.54 mg kg-1) whereas available Zn contents ranged from 0.1 to 78.2 mg kg-1 (median: 0.32 mg kg-1). The highest Pb and Zn concentrations were observed near Januária, in the northern part of the territory, probably on limestone rocks from the Bambuí group. Finally, the QRVs for Pb and Zn in natural soils were lower than their background values from other Brazilian region and below the prevention values suggested by Brazilian environmental regulations.
Collapse
Affiliation(s)
- Alba L A Skorupa
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Fábio H A Bispo
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Shirlei A Assunção
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Jakeline R Oliveira
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Francielle R D Lima
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Marcília B Teixeira
- Department of Exact Sciences, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Luiz R G Guilherme
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - José R S Scolforo
- Department of Forest Sciences, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - Yuri L Zinn
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil
| | - João José Marques
- Department of Soil Science, Universidade Federal de Lavras, Lavras, Minas Gerais, Brazil.
| |
Collapse
|