Contribution of isotopic geochemistry to the origin of lead in the atmosphere of Sicily

Air quality can be assessed using mineral and biological indicators: airborne particulate matter, mosses, lichens, and pine needles. However, the origin of the pollutant is usually difficult to determine on the sole basis of concentrations, particularly when many sources are involved. In this study, we report some examples of application of lead isotopic geochemistry on airborne particulate matter, lichens and pine needles as a mean to decipher sources of lead pollution in Sicily. Furthermore, we evaluate the use of Pb/Sc and Pb/Br ratios to enhance the discriminating power of the isotopic method. Besides the methodological aspect, this work aims to provide, at least for lead, a summary of the air quality in Sicily where only few investigations have been conducted, and to create an isotopic database.