Samples of lichen species (Xanthoria parietina) collected from Aegean Region of Turkey were analyzed by instrumental neutron activation analysis to determine the concentrations of 31 elements. The elements (Au, Rb, Zn, Hg, Sb, Cd, As, Cl, Br, and Se) showed enrichment with respect to the crustal composition. It has been hypothesized that lichen data can be examined more meaningfully without the inclusion of elements K, Mg, Ca, and Mn in the factor analysis. Four factors explaning 77.2% of the total variance were identified. The first factor represented the crustal elements Al, Na, Sc, Cr, Fe, La, and Sm along with contaminated soil with loadings of As, V, and Sb. The second factor was associated with mixed emissions including iron works (Cr, Zn, and Sb) and coal burning (As and Sb). The source profile of factor 3 was a strong marine component characterized by the elements Na, Cl, and Br. The factor 4, identified as regional background, contained the high loadings of As, Se, and Sb due to long-range transport of pariculate matter. These findings were supported by the geographical distribution of factor score maps.