Polycyclic aromatic hydrocarbons in Laurus nobilis leaves as a measure of air pollution in urban and rural sites of Tuscany

The levels of 9 polycyclic aromatic hydrocarbons (PAHs) 6 of which carcinogenic were measured in the leaves of evergreen tree (Laurus nobilis) sampled in 13 locations in summer and winter in Tuscany, Italy. The carcinogenic PAH levels were correlated with the PAH air levels sampled at the same site. Samples from larger towns had higher PAH levels than those from medium and small towns. Leaves collected in the center of larger cities had higher carcinogenic PAH levels than samples from residential areas indicating that vehicular traffic is the main PAH source. Carcinogenic PAH levels in leaves collected in the winter in medium towns were considerably higher than expected, probably due to domestic heating. These findings demonstrate that air quality in terms of PAH contamination is not markedly different in towns of different size in Tuscany.