Earthworms as useful bioindicator of soils contamination around Košice city, Slovakia

This study was conducted to investigate heavy metals bioaccumulation in industrialized soils in surrounding of Kosice city (Slovakia), using earthworms. In the present research, we used ecotoxicity tests with Dendrobaena veneta (7 and 28-day bioassays) to infer about potential toxic risks to the agricultural (A) and permanent grass vegetation (PGV) of soils around the plant U. S. Steel Kosice. The total Fe, Cu, Zn, Pb, Cd, Cr and As contents and eco-toxicological tests of industrialized soils from the Kosice area were performed for 12 sampling sites in years 2016 – 2017. An influence of the sampling sites distance from the largest steel producer plant on the total concentrations of heavy metals was determined for Fe, Cd, Cr and As. It was found that earthworms (Dendrobaena veneta) in some cases caused a decrease of metals concentration in contaminated soils, the largest metal concentration differences were recorded in the samples PGV (4) U. S. Steel-plant-main gate. The results of the bioaccumulation factors of heavy metals in D. veneta (BAFs/7-28 d) are 1 for Zn > Cd.