LAUSR

Three lichen species (Phaeophyscia orbicularis, Physcia adscendens, and Xanthoria parietina), were sampled from the deciduous trees along nine streets of various traffic densities in Prešov, Slovakia. The total concentrations of risk elements (Al, As, Ba, Cd, Cr, Cu, Fe, Li, Mn, Ni, Pb, Zn) were determined by the ICP-OES method. Phaeophyscia orbicularis showed the best ability to accumulate all evaluated risk elements except Pb and Cr. X. parientina was found to be the least suitable for bioaccumulation purposes. The concentration of evaluated risk elements in lichen insoles came predominantly from traffic, which was confirmed by a significant positive correlation between risk elements and traffic density. Based on the results of contamination factor, evaluated streets were most polluted by Cr, Fe, Ni, Pb and Zn and only slightly polluted by Cd. Provably higher values of Cd, Cu, Fe, Ni and Zn were measured in streets with higher traffic density. According to the cluster analysis, two groups of risk elements, expressing their origin, were found.