USE OF LICHENS IN DETECTING ENVIRONMENTAL RISK AND IN GEOCHEMICAL PROSPECTING

This paper provides data on variations in the contents of As, Sb, Ni, V, Pb, Cu, Cr, Au, Zn, Sc, and Al, measured in the thalli of a saxicol ous lichen species, Xanthoria calcicola Ochsner s.l., collected in nor theastern Sicily, near an industrial zone and along a belt crossing ar eas of known ores containing sulfides of heavy metals. A total of 91 l ichen samples were collected on roof tiles (39) and on rocks (52). In the industrial zone, analysis of lichen thalli revealed high contents of nickel and vanadium, decreasing at increasing distances from the so urce of contamination. The results have also revealed the versatility of Xanthoria calcicola in geochemical prospecting for heavy metals suc h as Pb, Zn, As, Au, Sb, Ni, V, and Cu. The contents of these elements in the analyzed lichens highlight the same geochemical associations o bserved in prospecting surveys on samples of river sediments and ident ify similar anomalies. Interpretation of data in terms of enrichment f actors (EFs) turned out to be particularly useful.