CECCATO D

MASIOL M

PAVONI B

RAMPAZZO G

SQUIZZATO S

English

Archivio istituzionale della ricerca - Università degli Studi di Venezia Ca' Foscari

Local and Regional Sources of Respirable Particulate Matter in VenicePreliminary Results of F-GAP(x) Experiments at the AN2000 AcceleratorM. Masiol1, S. Squizzato1, D. Ceccato2, G. Rampazzo1, B. Pavoni1.1Dipartimento di Scienze Ambientali, Informatica e Statistica, Università Ca’ Foscari Venezia, Venezia, Italy.2Dipartimento di Fisica, Università di Padova, Padova, Italy. 3INFN, Laboratori Nazionali di Legnaro, Legnaro (Padova), Italy.LNL Annual ReportNuclear Physics 1BACKGROUNDAtmospheric particles with an aerodynamic diameter lessthan 10 μm PM10 are named ”respirable fraction” becausethey can be inhaled and then enter the human respiratorytract. Whereas the largest particles are trapped in theupper respiratory tract (nose, throat and trachea), the finestones tend to penetrate deeper down to the alveolar region.The Council Directive 1999/30/EC has recommended themonitoring of PM10 in Europe, and the recently adopted2008/50/EC has attributed great importance to the finestfraction (with an aerodynamic diameter less than 2.5 μm,PM2.5.F-GAP(x) EXPERIMENTSF-GAP (2007–2009) and F-GAP2 (2011–2012)experiments at LNL [1, 2] mainly dealt with the geochemicalcharacterization of the PM10 in the Venice area and thequantification of the main sources that caused the frequentevents of PM concentrations above the EU limits. Thisreport presents some preliminary results of an extensivesampling campaign carried out in a semi-rural coastal sitenear Venice. Data obtained from the AN2000 PIXE facilityat LNL were processed by applying some receptor modelingtechniques and other chemometric tools to detect the mainemission sources having an effect on PM10 levels.EXPERIMENTALAbout one year-long PM10 sampling campaign (May2007–February 2008) was carried out in a coastal site nearVenice using a low volume sampler (TCR Tecora, Italy)and polycarbonate membranes (Ø 47 mm, 0.4 μm porosity,GE, USA). PM10 masses were gravimetrically determinedin conditioned temperature and relative humidity. Halfsample was ultrasonically extracted in ultrapure water andsolutions were analyzed for four anions (F−, Cl−, NO−3 ,SO2−4 ) and four cations (Na+, NH+4 , K+, Mg2+) using aion chromatography system (Dionex DX500, USA), afterpre-filtration.Samples were also analyzed for quantifying 17 elements(Na, Mg, Al, Si, P, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Brand Pb) using the AN2000 PIXE facility on the +45° beamchannel. Adopted FISAMB instrumental set-up was welldescribed in previous studies [3]. Energy resolution was 140eV at 5.9 KeV. GUPIX code was used to fit the X-ray energyspectra.Filter blank and fields blank were prepared in parallelwith the samples and subtracted in all analyses. The qualityand accuracy of quantitative analyses were checked withstandard reference materials (SRMs 1648 and 2783, NIST,USA). Details of chromatography and PIXE set-up weregiven elsewere [1–3].This report shows some preliminary data of F-GAP(x)experiments. The most probable sources of respirableparticulate matter were studied by applying somemultivariate procedures, including some widely usedreceptor modeling techniques. Data were studied separatelyfor warm and cold seasons. Warm period (May–beginningof September) shows typical atmospheric circulationpatterns with sea/land breezes. This period is thereforevery complex in terms of atmospheric circulation. Thecold season (October–January) is characterized by a lesscomplex atmospheric circulation, but is affected by thehighest levels of PM10, and is therefore more important interms of potential health hazard.FACTOR ANALYSIS AND UNMIXBoth periods were studied by applying the Varimaxrotated factor analysis (FA) which is the most common andwidely used approach to detect the main sources of PM10[1, 2]. In a second step, the same dataset was fed intothe receptor model UNMIX version 6 to solve the generalmixture problem in which data are assumed to be a linearcombination of an unknown number of emission sourcesof unknown composition, which contribute an unknownamount to each sample. UNMIX was well describedelsewere [4]. Results are very similar to those obtained withthe use of factor analysis.Generally, four factor with eigenvalues>1 were extractedfor the warm period, whereas a more complex sourcecomposition (six sources) was found in the cold season. Theobtained factor loadings for both periods are shown in fig. 1.Both periods exhibit a clear sea-salt source, which isnaturally originated by the bursting of bubbles at the seasurface. This source, similar to the seawater composition,is mainly composed of chloride, sodium and magnesium. Asecond natural source, the mineral dust, was also found inboth periods having high loadings of typical crustal markers:silicon and aluminium. However, for this latter source somedifferences in chemical profiles between warm and coldseasons were observed. Generally,the warm profile appearsmore complex, with high loadings for other crustal-like         45°  ted I  instr ental t    in previou  studies [3]. Energy resolution was140 eV at 5.9 KeV. GUPIX code was used to fit the X- a  en rgy spectra. [1] M. Masiol et al., Chemosphere 80 (2010) 771.[2] M. Masiol et al., Atmos. Environ 54 (2012) 127.[3] P. Mittner et al., Nucl. Instr. and Meth. B 109/110 (1996) 375.[4] R.C. Henry, Chemometr. Intell. Lab. 65 (2003) 179189.[5] G. Rampazzo et al., Water Air Soil Pollut. 195 (2008) 161.[6] G. Rampazzo et al., Chemosphere 71 (2008) 2068.[7] M. Masiol et al., Environ. Sci. Pollut. Res., in press.LNL Annual Report Nuclear Physics2season. The first source is made up of nitrate andammonium, clearly representing the ammonium nitrateformed through the condensation and the nucleation ofgaseous HNO3 and NH3 in the atmosphere [2]. The secondone is mainly composed of potassium, with moderateloadings of Cu and sulfate. As potassium has been largelyused as a tracer for biomass combustions, this source mayidentify mixed combustion processes.LOCAL AND REMOTE CONTRIBUTIONSAs recently reported [1, 2, 7], both local atmosphericcirculation and regional-scale transport can stronglyinfluence the air quality of Venice. Up today, many toolshave been proposed to study and assess the influences ofthese transport processes. Recently, the authors applied afactor-cluster analysis on chemical data and cluster analyseson wind data and backward trajectories. The results revealedthe important role of both local atmospheric circulation,i.e. weather conditions (air temperature, humidity, solarirradiation) and winds on the levels of PM10 in the studyarea. Moreover, also the external transports were foundhaving a significant impact on the air pollution levels,especially in the sampling days when EU limits wereexceeded.ACKNOWLEDGMENTSThe authors wish to thank Comando Zona Farie Segnalamenti Marittimi di Venezia (Marina MilitareItaliana) for logistics and ARPAV–Centro Meteorologico diTeolo for providing the weather data used in this study.Fig. 1. Factor loading extracted by FA for warm (grey) and cold(black) seasons.elements (K, Ca, Mn, Fe and Mg2+), whereas the coldprofile shows high shares of sulfate. These differencescan be mainly attributed to the higher air temperatures insummer, which may enhance the soil depletion and the roaddust resuspension.The third common factor clearly reflects an anthropogenicsource, having high loadings of Cr, Mn, Fe, Cu and Zn.This association of elements has been found in other studiesand interpreted as industrial or road traffic. However,since the sampling site is upwind to main industrial areas,traffic appears the most probable one [1, 2, 5, 6]. Thelast common source links vanadium and nickel, whichare widely known tracers of fuel-oil combustion, shippingemissions, petrochemical refineries and coke production.The concurrent moderate shares of sulfate and ammoniumconfirm the hypothesis that this source is related to the fossilfuels burning and conversion processes [1, 2].Two additional sources were found during the cold weather conditions (air te perat r , i  

Local and Regional Sources of Respirable Particulate Matter in Venice Preliminary Results of F-GAP(x) Experiments at the AN2000 Accelerator

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Local and Regional Sources of Respirable Particulate Matter in Venice Preliminary Results of F-GAP(x) Experiments at the AN2000 Accelerator

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