Chemical and morphological characterization of PM in Apulia Region

Several epidemiological studies have shown the negative effect of Particulate Matter (PM) on human health; in particular, it was shown that the finer fractions of PM (PM2.5 and PM1) can penetrate deeply into the lung and cause negative effects which ranges from cardiovascular and neurotoxic effects to cancer (Künzli and Perez, 2009). For this reason, plans to suggest right policy controls for human health protection have to taken into account the most relevant emission sources for the area under investigation and how PM concentrations at receptors can be influenced by transport, mixing and transformation processes. In this work, the collaboration among different partners, such as Apulian Agency for Environmental Protection, University of Bari, University of Lecce, CNR-ISAC, allowed to obtain important results by a PM monitoring campaign performed in Apulia Region. PM10 has been collected in five different sampling sites (Torchiarolo, Galatina, Taranto- Tamburi, Palagiano e Montalbano-Ostuni) at different distance from the iron and steel pole of Taranto. The main interest on Taranto is due to the presence of several activities of high impact as very wide industrial area close to the town and the numerous maritime and military activities in the harbour area (Amodio et al., 2008). Therefore, the aim of this study was the chemical characterization of PM10 samples in order to estimate emission sources contributions and to evaluate how these sources influence pollutants concentrations at the sampling sites. Fifteen daily samples have been collected in the period from February 2009 to March 2009. The chemical characterization of the samples has been performed to determine inorganic components, Polycyclic Aromatic Hydrocarbons, carbonaceous fractions and metals. It was found that the sampling site close to the steel plant (Taranto-Tamburi) was affected by iron and manganese concentrations greater than those observed in other sites (an order of magnitude) when the wind direction allowed the transport from the plant to the receptor. The contribution of crustal matter source has been evaluated by means of titanium and silicon concentrations: almost the same values were observed in the different sites and it was explained according to a regional contribution of this source. On the contrary, the chemical concentrations of sodium and chlorine allowed to highlight the local contributions of marine aerosol. Finally, the relevance of biomass burning for domestic heating in the sampling site of Torchiarolo e Galatina has been shown by high concentrations of PAHs and potassium, in agreement with high aluminium concentrations. Moreover, SEM - EDS analysis allowed the morphological characterization of PM: the collected images were used both to obtain particles statistical size and shape distributions and to characterize chemical species. In the sampling period, Comprehensive Air Quality Model with extensions (CAMX) was used to evaluate meteorological dispersion condition of the atmosphere. Starting and edge domain concentrations of chemical species have been evaluated by taking into account data obtained by CHIMERE model. Source emissions data, available in Apulia Region Emission Inventory, were processed by means of GEM-PP code. Measured pollutants concentrations were compared to those obtained by applying the model and the underestimation of real concentrations were observed. It was explained taking into account some sources not considered in Emission Inventory and the chemical mechanism, performed by the model, for the simulation of secondary particulate matter formation. Künzli, N., Perez, L., (2009). Swiss Medical Weekly 139(17-18), 242-250. Amodio, M. et al., (2008). ChemiChemical Engineering Transactions 16, 193-199.