Elsevier, European Journal of Soil Biology, (53), p. 32-39
DOI: 10.1016/j.ejsobi.2012.08.004
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a b s t r a c t To investigate the effect of the soil passage through the gut of earthworms (Pontoscolex corethrurus) on the forms of Pb and Mn, casts and soil samples were analyzed by sequential extraction procedure. Soil samples were collected in an area under direct influence of mining and metallurgy of Pb in the Parana state, Brazil. The earthworms were incubated with the soils to collect castings. The Pb and Mn concentrations were determined in seven sequential phases: soluble; exchangeable; carbonate; organic matter; Fe and Mn oxides; Al oxides and aluminosilicates; residual. There was intense contamination with Pb in the area, mainly in the clayish soil surrounding the factory by the deposition of suspended material coming from the chimneys (maximum concentration 9716 mg kg À1). On the other hand, total concentration of soil Mn was little influenced by the mining and metallurgy activities in the area. The earthworms significantly reduced the amount of Pb in the soluble and exchangeable forms in the soil, considered environmentally more bioavailable. There was also a significant increase in Pb bound in Fe and Mn oxides in the casts (specific absorption), which is desirable for soil bioremediation. Ó 2012 Elsevier Masson SAS. All rights reserved.