Abstract

Atmospheric aerosols have potential effects on human health, on the radiation balance, on climate, and on visibility.The understanding of these effects requires detailed knowledge of aerosol composition and size distributionsand of how the different sources contribute to particles of different sizes. In this work, aerosol sampleswere collected using a 10-stage Micro-Orifice Uniform Deposit Impactor (MOUDI). Measurements were takenbetween February and October 2011 in an urban background site near Lecce (Apulia region, southeast of Italy).Samples were analysed to evaluate the concentrations of water-soluble ions (SO4 2-, NO3-, NH4+, Cl-, Na+, K+,Mg2+ and Ca2+) and of water-soluble organic and inorganic carbon. The aerosols were characterised by twomodes, an accumulation mode having a mass median diameter (MMD) of 0.35 ± 0.02 ?m, representing51 ± 4% of the aerosols and a coarse mode (MMD = 4.5 ± 0.4 ?m), representing 49 ± 4% of the aerosols.The data were used to estimate the losses in the impactor by comparison with a low-volume sampler. The averageloss in the MOUDI-collected aerosol was 19 ± 2%, and the largest loss was observed for NO3- (35 ± 10%).Significant losses were observed for Ca2+ (16 ± 5%), SO4 2 - (19 ± 5%) and K+ (10 ± 4%), whereas the lossesfor Na+ and Mg2+ were negligible. Size-segregated source apportionment was performed using Positive MatrixFactorization (PMF), which was applied separately to the coarse (size interval 1-18 ?m) and accumulation (sizeinterval 0.056-1 ?m) modes. The PMF model was able to reasonably reconstruct the concentration in each sizerange.The uncertainties in the source apportionment due to impactor losseswere evaluated. In the accumulationmode, it was not possible to distinguish the traffic contribution from other combustion sources. In the coarsemode, it was not possible to efficiently separate nitrate from the contribution of crustal/resuspension origin.

Autore Pugliese

• Cesari Daniela , Contini Daniele , Ielpo Pierina

Tutti gli autori

• Contini D.; Cesari D.; Genga A.; Siciliano M.; Ielpo P.; Guascito M.R.; Conte M.

Titolo volume/Rivista

Science of the total environment

Anno di pubblicazione

2014

ISSN

0048-9697

ISBN

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Numero di citazioni Wos

Nessuna citazione

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Settori ERC

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Codici ASJC

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