Assessment of quality of air in Palermo by chemical (ICP-OES) and cytological analyses on leaves of Eucalyptus camaldulensis.

In this work, we studied the influence of air pollution on the morpho-structural, biochemical and chemical composition of Eucalyptus camaldulensis leaves. Analyses were carried out on 22 samples collected in Palermo (Italy) area. Considering the mean concentrations (in unwashed leaves) of investigated metals, nutrient elements as Fe (214 mg kg(-1) dry weight (d.w.)), Mn (160 mg kg(-1) d.w.) and Zn (39 mg kg(-1) d.w.) were the most abundant, whereas Pb (5.6 mg kg(-1) d.w.) and Cd (0.072 mg kg(-1) d.w.) showed the lowest concentrations. The values of metal pollution index (MPI) ranged from 6.0 (station no. 15) to 25 (station no. 8) and from 4.0 (station no. 16) to 17 (stations no. 7 and no. 15) for unwashed and washed leaves, respectively. The station no. 8, located in an area interested by traffic mostly caused by the activities of university, showed the highest value of MPI. The station no. 15 (Industrial area) showed the lowest MPI value, which is similar to those determined in the reference stations. Considering that the station considered is located in a large and open area interested only by commercial activities and there are no production activities, this data is not surprising. In this study, the washing of the leaves with distilled water has caused a little reduction of metal concentrations. Microphotography reveals a correlation between zones of necrosis, modified cuticles and accumulations of acid phosphatases in the leaves collected in polluted areas. The diaphanized leaves from the more polluted areas show irregular areolas, several idioblasts both on the ribs and scattered in the mesophyll. With polarized light, we observe many crystal deposits near the ribs.