Outdoor spatial distribution and indoor levels of NO2 and SO2 in a high environmental risk site of the South Italy.

In the frame of the project EDOC@WORK3.0, Education and Work on Cloud, a monitoring plan has been carried out in the highly industrialized town of Taranto (one of the most polluted sites of Italy) in order to investigate contemporary indoor and outdoor concentrations of NO2 and SO2 by passive sampling devises (Radiello). Simultaneously indoor and outdoor samplings of NO2 and SO2 were performed from 2nd November 2015 to 2nd December 2015 in nine sites scattered in the investigated area at different quotes and distances from the industrial complex. Our findings show substantial differences between the spatial distributions of the two pollutants and support the hypothesis of two different prevalent sources for NO2 and SO2. In particular, we find diffusive sources of NO2 linked mainly to the vehicular traffic and secondarily to industrial sources. In contrast, SO2 was mainly associated to industrial sources present in the area, representing also a proxy of the mixture of air contaminants associated to industrial processes. Our hypothesis is also confirmed by analysis of data measured by ARPA air quality monitoring stations. Comparison between indoor and outdoor concentrations confirms that outdoor pollutants infiltrate to indoor environments, moreover it highlights potential NO2 indoor sources basically linked to cooking activities, representing adverse health effects for population risk categories such as children or cooks. Considering that urban people spend a lot of their time in indoors, attention should be paid both to outdoor pollutant sources and to indoor sources.

Source apportionment of PM(2.5) in the harbour-industrial area of Brindisi (Italy): identification and estimation of the contribution of in-port ship emissions.

Harbours are important for economic and social development of coastal areas but they also represent an anthropogenic source of emissions often located near urban centres and industrial areas. This increases the difficulties in distinguishing the harbour contribution with respect to other sources. The aim of this work is the characterisation of main sources of PM2.5 acting on the Brindisi harbour-industrial area, trying to pinpoint the contribution of in-port ship emissions to primary and secondary PM2.5. Brindisi is an important port-city of the Adriatic Sea considered a hot-spot for anthropogenic environmental pressures at National level. Measurements were performed collecting PM2.5 samples and characterising the concentrations of 23 chemical species (water soluble organic and inorganic carbon; major ions: SO4(2-), NO3(-), NH4(+), Cl(-), C2O4(2-), Na(+), K(+), Mg(2+), Ca(2+); and elements: Ni, Cu, V, Mn, As, Pb, Cr, Sb, Fe, Al, Zn, and Ti). These species represent, on average, 51.4% of PM2.5 and were used for source apportionment via PMF. The contributions of eight sources were estimated: crustal (16.4±0.9% of PM2.5), aged marine (2.6±0.5%), crustal carbonates (7.7±0.3%), ammonium sulphate (27.3±0.8%), biomass burning-fires (11.7±0.7%), traffic (16.4±1.7 %), industrial (0.4±0.3%) and a mixed source oil combustion-industrial including ship emissions in harbour (15.3±1.3%). The PMF did not separate the in-port ship emission contribution from industrial releases. The correlation of estimated contribution with meteorology showed directionality with an increase of oil combustion and sulphate contribution in the harbour direction with respect to the direction of the urban area and an increase of the V/Ni ratio. This allowed for the use of V as marker of primary ship contribution to PM2.5 (2.8%+/-1.1%). The secondary contribution of oil combustion to non-sea-salt-sulphate, nssSO4(2-), was estimated to be 1.3 µg/m(3) (about 40% of total nssSO4(2-) or 11% of PM2.5).

Source apportionment of size-segregated atmospheric particles based on the major water-soluble components in Lecce (Italy).

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 distributions and of how the different sources contribute to particles of different sizes. In this work, aerosol samples were collected using a 10-stage Micro-Orifice Uniform Deposit Impactor (MOUDI). Measurements were taken between 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(+), Mg(2+) and Ca(2+)) and of water-soluble organic and inorganic carbon. The aerosols were characterised by two modes, an accumulation mode having a mass median diameter (MMD) of 0.35 ± 0.02 µm, representing 51 ± 4% of the aerosols and a coarse mode (MMD=4.5 ± 0.4 µm), 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 average loss in the MOUDI-collected aerosol was 19 ± 2%, and the largest loss was observed for NO3(-) (35 ± 10%). Significant losses were observed for Ca(2+) (16 ± 5%), SO4(2-) (19 ± 5%) and K(+) (10 ± 4%), whereas the losses for Na(+) and Mg(2+) were negligible. Size-segregated source apportionment was performed using Positive Matrix Factorization (PMF), which was applied separately to the coarse (size interval 1-18 µm) and accumulation (size interval 0.056-1 µm) modes. The PMF model was able to reasonably reconstruct the concentration in each size-range. The uncertainties in the source apportionment due to impactor losses were evaluated. In the accumulation mode, it was not possible to distinguish the traffic contribution from other combustion sources. In the coarse mode, it was not possible to efficiently separate nitrate from the contribution of crustal/resuspension origin.

Analysis of heavy metals in atmospheric particulate by ion chromatography.

Cu, Ni, Zn, Co, Fe+2, Mn, Cd, Fe+3 and Pb are easily separated and detected in isocratic mode by ion chromatography with post-column derivatization using a bifunctional ion-exchange column and an eluent formed by oxalic acid (28 mM) and sodium nitrate (250 mM). The separation is optimised by using a suggested sample solution containing a given concentration of chloride. Detection limits were 10-15 ppb for all the metals except for cadmium and lead, for which detection limits of 30 and 60 ppb were found, respectively. The method was tested on an atmospheric particulate certified sample. The measured values were in good agreement with certified values. Real samples of atmospheric particulate from industrial and urban sites were analysed and the results are discussed.