title: The size distribution of chemical elements of atmospheric aerosol at a semi-rural coastal site in Venice (Italy). The role of atmospheric circulation.
abstract: The concentrations of selected elemental tracers were determined in the aerosol of a semi-rural coastal site near Venice (Italy). Size-segregated aerosol samples were collected using an 8-stage cascade impactor set at 15m above ground, during the cold season (late autumn and winter), when high levels of many pollutants are known to cause risks for human health. From the experimental data, information was extracted on potential pollutant sources by investigating the relationships between elements in the different size fractions. Moreover, an approach to highlight the importance of local atmospheric circulation and air mass origin in influencing the PM composition and fractional distribution is proposed. Anthropogenic elements are strongly inter-correlated in the submicrometric (<1 μm) (S, K, Mn, Cu, Fe and Zn) and intermediate mode (1-4 μm) (Mn, Cu, Zn, Ni) and their relationships highlight the presence of several sources (combustions, secondary aerosol, road traffic). In the intermediate mode, associations having geochemical significance exist between marine (Na, Cl and Mg) and crustal (Si, Mg, Ca, Al, Ti and K) elements. In the coarse mode (>4 μm) Fe and Zn are well correlated and are probably linked to tire and brake wear emissions. Regarding atmospheric circulation, results show increasing levels of elements related to pollution sources (S, K, Mn, Ni, Cu, Zn) when air masses come from Central and Eastern Europe direction and on the ground wind blows from NWN-N-NE (from mainland Venice). Low wind speed and high percentage of wind calm hours favor element accumulation in the submicrometric and intermediate modes. Furthermore, strong winds favor the formation of sea-spray and the increase of Si in the coarse mode due to the resuspension of sand fine particles.
authors: Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, Dorsoduro 2137, 30123 Venice, Italy.
authors: Mauro
authors: M
authors: Masiol
authors: Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, Dorsoduro 2137, 30123 Venice, Italy. Electronic address: stefania.squizzato@unive.it.
authors: Stefania
authors: S
authors: Squizzato
authors: Dipartimento di Fisica e Astronomia "Galileo Galilei", Università degli Studi di Padova, Via Marzolo 8, 35100 Padua, Italy; Laboratori Nazionali di Legnaro, Istituto Nazionale di Fisica Nucleare, Viale dell'Università 2, 35020 Legnaro, Italy.
authors: Daniele
authors: D
authors: Ceccato
authors: Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca' Foscari Venezia, Dorsoduro 2137, 30123 Venice, Italy.
authors: Bruno
authors: B
authors: Pavoni
mesh_terms: D000336:Aerosols / Q000032:analysis; D000392:Air Movements; D000393:Air Pollutants / Q000032:analysis*; D004784:Environmental Monitoring; D007558:Italy; D010316:Particle Size; D052638:Particulate Matter / Q000032:analysis*
chemical_list: D000336:Aerosols; D000393:Air Pollutants; D052638:Particulate Matter
keywords: Element mass size distributions; Lagoon of Venice; Meteorological conditions; PIXE analysis