Leaf contamination by atmospheric pollutants as assessed by elemental analysis of leaf tissue, leaf surface deposit and soil

In order to evaluate the influence of air pollutants influx on leaf elemental composition, the concentration of N, S, Cu, Fe and Pb were analyzed in the surface deposit and tissue of Quercus ilex L. leaves from 8 sites of the urban area of Naples. The soil from the trunk base area of Q. ilex trees in the same sites was also analyzed for total contents of N and S and for available contents of Cu, Fe and Pb. In the leaf surface deposit S content was high though significantly (P<0.001) lower than in the leaf tissue, whilst N was not detectable. Cu, Pb and Fe contents in leaf surface deposit were conspicuous. The Pb content was higher in the leaf surface deposit than in the leaf tissue. No correlation between leaf tissue and surface deposit contents was found for S or for Fe. By contrast, positive and significant correlations (P