B. E. Daresta

Application of CMB Model to PM10 Data Collected in a Site of South Italy: Results and Comparison with APCS Model

Chemical mass balance modeling (CMB) was applied to determine the PM10 sources and their contributions. PM10 samples were collected in Lecce (South Italy) during two monitoring campaigns performed in the months of July 2005 and February 2006. Nine source profiles and average mass concentration of the following chemical parameters: EC, OC, Cl - , NO 3 - , SO 4 2- , Na + , NH 4 + , K + , Mg 2+ , Ca 2+ , Al, Si, Ti, V, Mn, Fe, Cu, Pb, and Zn were used to run the Chemical Mass Balance (CMB 8 ) model. The results obtained by application of CMB 8.2 to one sample data (L21) are shown. The contributions to PM10 show that dominant contributor was traffic with 37% followed by petroleum industry with 19% and field burning with 16%. Minor source contributions were marine aerosol (1%), ammonium sulfate production (4%), ammonium nitrate production (11%), oilfired power plant (0.1%), gypsum handling (10%) and crustal (2%).

Different effects of polycyclic aromatic hydrocarbons in artificial and in environmental mixtures on the free living nematode C. elegans

Polycyclic aromatic hydrocarbons (PAHs) are known to exert mutagenic and carcinogenic effects. Research on extracted organic matter (EOM) from environmental mixtures has indicated several mechanisms of intracellular damage in living organisms. The toxic effect of environmental pollutants is usually assessed on cell systems or in single species. We used the model organism Caenorhabditis elegans to compare the effect of synthetic PAHs with that of the EOM from environmental mixtures. The biological effect was measured by monitoring the expression level of some crucial genes, sensitive parameters of the organisms response. The results indicate the ability of C. elegans to counteract damage by mounting a stress‐response only in the presence of EOM. On the other hand the exposure of C. elegans to a mixture of synthetic PAHs determines the silencing of the transcriptional machinery, thus preventing the synthesis of proteins that are important for both the damage repair mechanism and survival itself. The results strongly indicate that the study of environmental toxicant effects at the molecular level may provide information on their mechanism of action. Copyright

Method for the Determination of Cu(II), Ni(II), Co(II), Fe(II), and Pd(II) at ppb/subppb Levels by Ion Chromatography

Abstract A method for the determination of Cu(II), Ni(II), Zn(II), Co(II), Fe(II), and Pd(II) at ppb/subppb levels by ion chromatography was developed, improving a previous work of the same authors. In order to lower the detection limits, the direct injection of a large sample volume (5 mL) and 4‐(2‐pyridylazo) resorcinol solution at pH 6, with hexadecylpyridinium chloride as the post‐column reagent were used. The obtained calibration curves were linear (for each metal R2≥0.99) with good reproducibility; the detection limits for Cu(II), Ni(II), Zn(II), Co(II), Fe(II), and Pd(II) were 1.1, 0.46, 39, 0.18, 4.5, and 1.7 ppb, respectively.

Role of the Ionic Component and Carbon Fractions in the Fine and Coarse Fractions of Particulate Matter for the Identification of Pollution Sources: Application of Receptor Models

Particulate matter (PM) is a very complex mixture of many inorganic and organic compounds of primary and secondary origin and this is the main reason why the desired reduction of its concentration and the identification of its many sources constitute a very difficult task. It is widely recognised that atmospheric particles are responsible for adverse effects on the ecosystem, the climate and the health of human beings (Pope & Dockery, 2006). Epidemiological studies have shown a consistent association of the mass concentration of urban air thoracic particles (PM10 particles with an aerodynamic diameter smaller than 10 μm), and its sub-fraction fine particles (PM2.5 particles with an aerodynamic diameter smaller than 2.5 μm), with mortality and morbidity among cardio-respiratory patients (WHO, 2005). Recent studies indicate that PM10 is associated to respiratory responses while PM2.5 may contribute to cardiovascular diseases (Wyzga, 2002). The chemical characteristics of the particulate fractions and biological mechanisms responsible for these adverse health effects are still unknown as well as the aerosol parameters (mass, particle size, surface area, etc) involved in the health impacts (Hauck et al., 2004). In addition, there is an indication that the increase in the atmospheric aerosol burden delays the global warming attributed to the increase in greenhouse gasses (GHG: CO2, CH4, N2O, halocarbons). Whether the increase in GHGs since preindustrial times is producing a warming of 2.3 Wm,anthropogenic contributions to aerosols (primarily sulphate, organic carbon, black carbon, nitrate and dust) together produce a cooling effect, with a total direct radiative forcing of -0.5 Wm2 and an indirect cloud albedo forcing of -0.7 Wm (IPCC, 2007). In recent years many studies have been carried out to determine the chemical composition of atmospheric particulate matter (Vecchi et al., 2007). Most of these studies were devoted to the identification of the main particle sources, with the purpose to identify viable strategies for their reduction. In this chapter we focus the attention mostly on the ionic component of