Analysis of heavy metals in atmospheric particulates in relation to their bioaccumulation in explanted Pseudevernia furfuracea thalli.

Lichens explants and airborne particulates were analysed for Cr, Zn, Cd, Pb, Ni, Fe, Mn and Cu content in a rural site in the province of Vercelli (Piedmont, N. Italy). Thalli of the fruticose lichen Pseudevernia furfuracea were collected from an uncontaminated area and exposed for one year using two different techniques. Particulates were collected using a continuously operating particulate sampler set up near the lichens explanted throughout the experiment survey. The results confirm both the importance of assessing contamination in rural areas corroborated by the analysis of the presence of the heavy metals in particulates in relation to the main wind directions and the validity of this lichen as biomonitor of airborne metal pollution, although meaningful differences were pointed out between the two different techniques of exposure. The significant correlation between most of the metals accumulated by lichens and the metal air concentrations shows a good evidence of their ability to represent atmospheric contamination.