Earthworm casts as a sampling medium - a case study from highly contaminated Hg roasting site Pšenk (Idrija area, Slovenia)
AbstractIn this study an interesting sampling medium - earthworm casts was examined in a highly Hg contaminated area. Enrichment factor (EF) has been applied to assess elevated concentrations of analyzed elements in earthworm casts and to determine elevated concentrations of these elements in soils and casts with regard to European average concentrations in topsoil. In a previous study (Teršič & Gosar, 2012) it was shown that Hg contents and dispersion in casts from studied roasting site are comparable to those in soil, which indicates that soil contamination is substantially reflected in contamination of earthworm casts. Therefore the comparison between elemental concentrations in earthworm casts and soil was investigated with the intention to assess the reflection of possible soil contamination in casts. Besides Hg contamination, elevated concentrations of As, Ca, Cd, Mo, Pb and U were also determined in earthworm casts. The calculated EFs show moderate enrichment of casts with Ca, Sr and P and minimal enrichment with Mg, Zn and Cu. Cast, SOM (surface organic matter rich soil layer) and soil enrichments with regard to the European averages show extreme enrichment of all studied media with Hg, followed by significant enrichment with Mo and Cd and moderate enrichment with As. Spatial distributions of analyzed elements in casts mostly show similar pattern as in soil, however, because of the different nature of different earthworm species and specific properties of different elements, the data about cast contamination can only serve as an approximate prediction about the dispersion and distribution of contaminant in soil.
How to Cite
Teršič, T., & Gosar, M. (2013). Earthworm casts as a sampling medium - a case study from highly contaminated Hg roasting site Pšenk (Idrija area, Slovenia). Geologija, 56(2), 243–255. https://doi.org/10.5474/geologija.2013.016