Comparative of Local Background Values for Trace Elements in Different Brazilian Tropical Soils
Carlos Roberto Juchen1, Eduardo Cimino Cervi2, Marcio Antonio Vilas Boas3, Susanne Charlesworth4 and Cristiano Poleto5
1. Coordination of Chemical Processes-COPEQ, Federal Technological University of Paraná-UTFPR, Toledo, Paraná, 85902-490, Brazil
2. Science Center of Engineering Applied to Environment-CCEAMA, University of São Paulo-USP, Itirapina, São Paulo, 13560-970, Brazil
3. Center for Exact Sciences and Technology, Western Paraná State University-UNIOESTE, Cascavel, Paraná, 85819-110, Brazil
4. Centre for Agroecology, Water and Resilience, Coventry University, CV1 5FB, Coventry, England
5. Hydraulic Research Institute-IPH, Federal University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, 91501-970, Brazil
Abstract: Quality reference values support the establishment of soil screening levels for contaminants that may be used to identify areas needing further investigation. Determination of a unique background has been defined for individual elements across a whole country, such as Brazil, which could give rise to either over- or under-estimation of metal contamination. Due to the lack of local information that supports decision-making for polluted sites, the main purpose of this paper was to compare local background concentrations for trace elements in different Brazilian tropical soils. Background concentrations of trace elements from two sample sets of representative soils from different States in Brazil were analyzed. Sample digestion was based on the USEPA’s 3050B method with concentrations determined by ICP-AES. Results showed that trace element levels from Toledo, Paraná were lower than national reference values, with the exception of Cu and Ni. Arsenic from Viamão, Rio Grande do Sul had a mean of 55 mg kg-1 and was much higher than those from Toledo at <0.005 mg kg-1.Values for Viamão were therefore above the national threshold, which justifies the need for determining soil background at a local scale. The natural concentrations determined for both sets of soils can be used to define local backgrounds. Trace element levels may vary from location to location, due to different classes of soils and/or parent materials. Therefore, determine local background is necessary in order to draw any conclusions as to whether elevated element concentrations in soil are natural or anthropogenic.
Key words: Heavy metals, geochemical background, soil pollution, geochemistry.
Download: Purchase PDF - $ 5