Assessment of diffuse pollution associated with metals in urban sediments using the geoaccumulation index (Igeo)
- 508 Downloads
This study investigated the behavior of cadmium (Cd), lead (Pb), nickel (Ni), and zinc (Zn) in urban sediments collected in commercial, residential, and industrial areas of the city of Porto Alegre, Brazil, and evaluated different degrees of pollution in this urban subdrainage basin through the use of the geoaccumulation index (Igeo).
Materials and methods
Concentrations of Cd, Ni, Pb, and Zn were analyzed using acid digestion (EPA method 3050) in fractions <63 μm in 20 composite samples of urban sediment collected using a portable vacuum in 20 different sampling points on roads from three areas with diverse use: commercial, industrial, and residential.
Results and discussion
The values of Igeo were commercial area (3.35, Zn; 3.76, Cd; 3.60, Ni; 2.63, Pb) > residential area (3.34, Zn; 3.36, Cd; 2.94, Ni; 1.46, Pb) > industrial area (2.74, Zn; 1.78, Cd; 3.01, Ni; 1.45, Pb), indicating that the sediment was “highly contaminated” in the case of Zn and Ni, while for Cd, it was “moderately to highly contaminated,” and for Pb, it was “moderately contaminated.” The pollution is associated with traffic flow in all areas.
Research should be increased to make urban systems more sustainable, reducing their pollution potential and minimizing the delivery of potentially polluting particles into freshwater bodies. The Igeo allows for the determination of a simple index of diffuse pollution state associated with urban sediments.
KeywordsDiffuse pollution Enrichment indexes Urban drainage Urban sedimentology
The authors thank the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) for the financial support, to the Conselho Nacional de Desenvolvimento Cientifico e Tecnológico (CNPq) for granting a scholarship, and to the Soil Analysis Laboratory of the Universidade Federal do Rio Grande do Sul for performing the chemical analyses.
- Poleto C, Merten G (2008) Urban street pollutants. Pesquisas em geociências (ufrgs) 35:3–8Google Scholar