Environmental impact assessment of risk elements from railway transport with the use of pollution indices, a biotest and bioindicators

Abstract

The paper evaluates the accumulation of selected risk elements in soils and biological tissues caused by railway transport. Samples of soil, pine (Pinus sylvestris L.) bark and needles, hoof fungus (Fomes fomentarius L.) and red-stemmed feathermoss (Pleurozium schreberi L.) were analyzed for the content of Cd, Cr, Cu, Ni, Pb and Zn. The samples were collected in five sites (A, B, C, D, E each separated by 500 m) covering a combined distance of around 2 km along railway tracks (Central Poland). The geo-accumulation index (I geo), single pollution index (PI), contamination factor (Cf), degree of contamination (C deg), potential ecological risk (RI), and the probability of toxicity (MERMQ) index were calculated to determine soil pollution with risk elements. Soil toxicity was assessed with the Phytotoxkit biotest which measures the inhibition of seed germination and root growth in Sorghum saccharatum L. The calculated indices and the results of the phytotoxicity biotest revealed the highest levels of contamination in the proximity of a road overpass (site D). The accumulation of risk elements in soil was strongly correlated with pollutant levels in biological tissues. Zinc was the most abundant element in biological tissues, especially in pine bark and feathermoss. Soil pollution indices, biotest results, and plant and fungus bioindicators play an important role in environmental assessments of railway transport.