POLYNUCLEAR AROMATIC-HYDROCARBONS IN THE LEAVES OF THE EVERGREEN TREELAURUS-NOBILIS

The levels of 10 polynuclear aromatic hydrocarbons (PAHs), phenanthren e, fluorene, pyrene, benzo[a]anthracene, chrysene, benzo[b]fluoranthen e, benzo[k]fluoranthene, benzo[a]pyrene, dibenzo[a,h]anthracene and be nzo[g,h,i]perylene, were determined in the leaves of the bay evergreen tree (Laurus nobilis) taken from 15 different sites in the Valley of Florence. The measurements were repeated for three different seasons ( summer, autumn, winter). The concentration of all PAHs increased durin g the year with maximum levels occurring during the winter. The elemen tal analysis of the leaves (K, Si, P, S, Ca, Pb, Br, Mn, Fe, Sr, Zn, C u) showed a good correlation between PAHs and lead or bromine levels, indicating that the main source of PAHs deposited on the leaves was ve hicular traffic. The levels of PAHs on the leaves were also well corre lated with air levels at two different sites.