CHEMICAL AND TOXICOLOGICAL CHARACTERIZATION OF AIRBORNE TOTAL SUSPENDED PARTICULATE (TSP) AND PM_(10) ORGANIC EXTRACTS

摘要

The relationship between chemical composition of airborne particulates and the genotoxicity has been investigated in the atmosphere of Rome, Italy. For this purpose, both total suspended particulate (TSP) and the PM_(10) fractions were collected daily inside a green park located in downtown, grouped on a weekly basis and speciated for their burdens of polycyclic aromatic hydrocarbons (PAH) and nitro-PAH. Concurrently, the genotoxicity of the organic extracts was evaluated by the Comet assay (SCGE: single cell gel electrophoresis) on human peripheral blood mononuclear cells (PBMC). The results indicate that organic extracts were able to induce DNA damage and a cytotoxic effect on PBMC. The TSP fraction was more cytotoxic than PM_(10) while the genotoxicity of both fractions was comparable. The genotoxic potential of the different samples was highly correlated to the amount of total PAH (correlation coefficient = 0.87), carcinogenic PAH (correlation coefficient = 0.88), B(a)P (correlation coefficient = 0.87) and to a less extend to the concentration of 1-nitropyrene (correlation coefficient = 0.66). Theseasonal modulation suggests that in Rome the air is more toxic during winter, however in-the warm season oxidized species including nitro-PAHs (evolving from secondary pollution) seem to balance the decrease of PAH concentration rates.