Use of lead isotopic fingerprint in human scalp hair to identify potential sources of pollution in industrial Sicilian sites (Italy)

Petrochemical industries represent a controversial, although important, the economic resource. They offernumerous job opportunities, which in turn contribute to the economic development of the city. People living intowns close to industrial plants are particularly exposed to severe environmental decline, which involves thedeterioration of the quality of air, water, soil, and food. The municipalities of Augusta (SR), Gela (CL) and Pacedel Mela (ME) host large oil refineries, together with several important chemical and petrochemical industries.The main goal of this study is to evaluate if stable lead isotope ratios measured in the biological matrix can beused as pollution fingerprints. Total lead concentrations in 354 human scalp hair samples from adolescents (11–13 years old) belonging to both genders, along with 16 lead isotope analyses in hair samples from Augusta (6samples), Gela (6 samples) and Pace del Mela (4 samples) are discussed here. Pb concentrations of adolescentsliving at Pace del Mela resulted higher than those of adolescents living at Augusta and Gela (median valuesPbPM: 1.13 μg/g, PbAU: 0.36 μg/g and PbGL: 0.43 μg/g, respectively). Hair from adolescent living in the threeindustrial sites exhibited lead isotope ratios in the ranges 1.138–1.171 (average 1.157) for 206Pb/207Pb and2.093–2.122 (average 2.108) for 208Pb/206Pb. These values pointed to a multi-source mixing between bedrockparent material and industrial ash. In general, the results obtained confirm that the towns of Augusta, Gela andPace del Mela are heavily affected by industrial emissions. Moreover, the data endorse that the lead isotopemethod remains a powerful technique to identify potential sources of environmental contamination.