D. Ceccato

Characterization of PM10 sources in a coastal area near Venice (Italy): An application of factor-cluster analysis

In this study a factor-cluster analysis (FCA) applied to chemical composition of atmospheric particulate matter was carried out. Relating specific wind data and back-trajectories to the daily samples grouped using FCA can be useful in atmospheric pollution studies to identify polluting sources and better interpret source apportionment results. The elemental composition and water soluble inorganic ions content of PM(10) were determined in a coastal site near Venice during the sea/land breeze season. From the factor analysis four sources were identified: mineral dust, road traffic, fossil fuels and marine aerosol. From a hierarchical cluster analysis, applied on the factor scores, samples with a similar source profile were grouped. Five clusters were identified: four with samples highly characterized by one identified source, one interpreted as general background pollution. Finally, by interpreting cluster results with wind direction data and back-trajectory analysis further detailed information was obtained on potential source locations and possible links between meteorological conditions and PM(10) chemical composition variations were detected. The proposed approach can be useful for air quality assessment studies and PM(10) reduction strategies.

Defining the geochemical composition of the EPICA Dome C ice core dust during the last glacial‐interglacial cycle

The major element composition of the insoluble, windborne long-range dust archived in the European Project for Ice Coring in Antarctica Dome C ice core has been determined by Particle Induced X-ray Emission analyses. The geochemistry of dust from the last glacial maximum (LGM) and from the Holocene is discussed in terms of past environmental changes, throughout the last climatic cycle. Antarctic dust from glacial and interglacial climate clearly reveals different geochemical compositions. The weathered crustal-like signature of LGM dust is characterized by a low compositional variability, suggesting a dominant source under the glacial regime. The close correspondence between the major element composition of Antarctic glacial dust and the composition of southern South American sediments supports the hypothesis of a dominant role of this area as major dust supplier during cold conditions. Conversely, the major element composition of Holocene dust displays high variability and high Al content on average. This implies that an additional source could also play some role. Comparison with size-selected sediments suggests that a contribution from Australia is likely during warm times, when a reduced glacial erosion decreases the primary dust production and a more intense hydrological cycle and larger vegetation cover inactivates dust mobility in a large part of southern South America, weakening its contribution as a massive dust supplier to Antarctica.

PIGE-PIXE analysis of chewing sticks of pharmacological importance

Abstract PIGE and PIXE techniques were employed for the determination of the major, minor and trace elemental concentrations in chewing sticks of pharmacological importance namely: Butyrospermum paradoxum, Garcinia kola, Distemonanthus benthamianus, Bridelia ferruginea, Anogeissus leiocarpus, Terminalia glaucescens and Fagara rubescens, respectively. The concentration of fluorine which is very important for human dental enamel was specially determined using the 19F(p, p′γ)19F reaction. For decades these chewing sticks when used alone without toothpastes have proven to be very efficient, effective and reliable in cleaning the teeth of many people particularly in Nigeria and some other countries in Africa. The teeth of users are usually very strong, clean, fresh and devoid of germs and caries. Even with the advent of modern toothpastes with special additions of fluorine, the use of these popular and efficient chewing sticks is still unabated. Many people including the elite use them solely, a few others combine their use with modern toothpastes and brush. Proton beams produced by the 7 MV CN and 2.5 MV AN 2000 Van de Graaff accelerators at INFN, Laboratori Nazionali di Legnaro (LNL), Padova, Italy were used for the PIGE and PIXE analysis, respectively. Results of this novel study are presented and discussed.

PIGE-PIXE analysis of medicinal plants and vegetables of pharmacological importance

PIGE and PIXE techniques were employed to the study of elemental constituents of some traditional medicinal plants generally used in curing many diseases and ailments in southwestern Nigeria. Analyses were also carried out on commonly edible vegetables of medicinal and pharmacological importance. PIGE measurements were carried out using 3.5-MeV collimated protons from the 7 mV CN Van-de-Graaff accelerator of INFN, LNL, Legnaro (Padova), Italy, whereas the PIXE measurements were carried out using 1.8 MeV from the 2.5 MV AN 2000 Van-de-Graaff accelerator of the same laboratory. The results show that many of the medicinal plants contain elements of cardinal importance in human metabolism. The results from the vegetables also show the presence of vital elements that are needed for growth and development. In addition, some of the toxic elements, which include As, Cd, Hg, and so forth, were not detected. However, some of the recipes contain trace amounts of Pb at very low concentrations. This calls for proper control of dose rates in some samples to prevent the attendant negative cumulative effects.

The size distribution of chemical elements of atmospheric aerosol at a semi-rural coastal site in Venice (Italy). The role of atmospheric circulation

The concentrations of selected elemental tracers were determined in the aerosol of a semi-rural coastal site near Venice (Italy). Size-segregated aerosol samples were collected using an 8-stage cascade impactor set at 15m above ground, during the cold season (late autumn and winter), when high levels of many pollutants are known to cause risks for human health. From the experimental data, information was extracted on potential pollutant sources by investigating the relationships between elements in the different size fractions. Moreover, an approach to highlight the importance of local atmospheric circulation and air mass origin in influencing the PM composition and fractional distribution is proposed. Anthropogenic elements are strongly inter-correlated in the submicrometric (<1 μm) (S, K, Mn, Cu, Fe and Zn) and intermediate mode (1-4 μm) (Mn, Cu, Zn, Ni) and their relationships highlight the presence of several sources (combustions, secondary aerosol, road traffic). In the intermediate mode, associations having geochemical significance exist between marine (Na, Cl and Mg) and crustal (Si, Mg, Ca, Al, Ti and K) elements. In the coarse mode (>4 μm) Fe and Zn are well correlated and are probably linked to tire and brake wear emissions. Regarding atmospheric circulation, results show increasing levels of elements related to pollution sources (S, K, Mn, Ni, Cu, Zn) when air masses come from Central and Eastern Europe direction and on the ground wind blows from NWN-N-NE (from mainland Venice). Low wind speed and high percentage of wind calm hours favor element accumulation in the submicrometric and intermediate modes. Furthermore, strong winds favor the formation of sea-spray and the increase of Si in the coarse mode due to the resuspension of sand fine particles.

PIXE analysis of some medicinal plants used in cleaning teeth in southwestern Nigeria

Sixteen medicinal plants used for cleaning teeth in southwestern Nigeria were analyzed using the particle-induced X-ray emission (PIXE) technique. These medicinal plants have other therapeutic uses, but the emphasis and main focus were on their beneficial effects on human teeth. PIXE measurements were carried out using 1.8 MeV collimated proton beam from the 2.5 MV AN 2000 Van de Graaff accelerator at the Istituto Nazionale di Fisica Nucleare, Laboratori Nazionali di Legnaro, Padova Italy. The results showed the presence of 18 different elements at different concentrations, 2 plants had traces of gold, and none of the plants contained any toxic heavy metals. The metabolic roles of the detected elements were discussed especially as they affected the formation, growth, development, and protection of human teeth. The results of this study are presented and discussed.

Applications of PIXE, PIGE, SEM and EDAX techniques to the study of geological samples

Abstract The complementary nuclear techniques of PIXE, PIGE, SEM and EDAX were employed to the study of geological samples from Wuyo, North East of Nigeria. The geological samples studied include (i) sandstones (fresh, mylonised and silicified), (ii) granites (fresh and brecciated) and (iii) brecciated and uraniferous samples. The microstructure of the samples was studied using SEM, while PIXE, PIGE and EDAX gave the qualitative and quantitative geochemical data of the major, minor and trace elements in them. PIXE and PIGE measurements were carried out using proton beams produced by the 2.5 MV AN-2000 and 7 MV CN Van de Graaff accelerators at INFN-Laboratori Nazionali di Legnaro (LNL), Padova, Italy, respectively. The facilities at the same institute were used for the SEM and EDAX measurements. Results of this novel study are presented and discussed.

Coupling PIXE and SEM/EDAX for characterizing atmospheric aerosols in ice-cores

Abstract The atmospheric aerosol plays a key role in controlling the Earths climatic system. This climatic forcing is related to its dimension and chemical composition and therefore, understanding temporal and spatial fluctuations related to changing environmental conditions is a key step in assessing future climatic change. The atmospheres chemical constituents are deposited onto polar ice sheets, and conserved by accumulation of snow layers. Drillings in Greenland and Antarctica have provided long-term records of atmospheric constituents spanning the last 150 000 years. Within the framework of the Greenland Ice Core Project (GRIP), we have developed a methodology coupling PIXE to SEM-EDAX analysis for the characterization of the aerosols deposited in polar precipitation. In this paper, we present initial results on soluble/insoluble speciation for both Antarctic and Greenland samples. This study provides new information in the interpretation of ice core paleo-environmental records.

Studies on archaeological gold items found in Romanian territory using X-Ray-based analytical spectrometry

This paper is an overview of the work developed by our group in the investigations of museum objects and alluvial gold, reflected in a series of studies published between 2000–2011, supplemented with new results, unpublished up-to-date. The X-ray based spectrometric techniques employed range from various X-Ray Fluorescence (XRF) investigations to ion beam analysis, including synchrotron radiation XRF and micro-Particle Induced X-ray Emission. The gold objects discussed are mainly part of the Sarmizegetusa Dacian hoards—spiraled bracelets (armbands) and coins. After obtaining in 2011 the permission of the Romanian authorities to take very small (1–2 mg) samples from the most “unimportant” areas of the Dacian bracelets and several Koson staters, to analyze them by micro-SR-XRF at BESSY, in February 2012, the investigation of several micro-areas of 17 stater and 28 bracelet samples revealed important micro-structural inhomogeneity, especially in Sn and Cu. The same inhomogeneous micro-structure has been seen in Transylvanian alluvial gold. The analyses revealed details on the fingerprint of geological gold deposits and also the main characteristics of ancient gold metallurgy procedures used by the Dacians: a relatively low temperature (lower than Au melting point) and hammering during heating to obtain an ingot through sintering. The use of the sintering procedure was proved for the spiraled bracelets and the Koson without monogram coins, a tradition starting in the Bronze Age in Transylvanian gold processing. The existence of micro-inclusions of Ta-minerals in alluvial gold was also detected, explaining Ta trace presence in the artifacts from the Pietroasa hoard.

Tropospheric aerosol at Terra Nova Bay (Antarctica): Geochemical components and their time distributions during four summer seasons

Four aerosol sampling campaigns were performed in the summer season (November to February,93/94,94/95, 95/96,97/98) with a 12 h sampling time at a coastal site near to the Italian base of Terra Nova Bay. Despite the low aerosol concentrations,PIXE analysis allowed in all campaigns a principal components analysis based on elements Na, Mg,Al,Si,S,K,Ca and Fe,in which three principal components (PC) contribute at least 95% of the total variance. Each one of the six elements Na,Mg,Al,Si,S and Fe is significantly ( P 0.994) correlated to one of those PCs. This fact,together with the structure of the elemental profiles of the PCs,allows their geochemical identification with nonsea-salt S,sea-salt and crustal aerosol. Elements S,Na and Fe are convenient tracers of these PCs. One campaign displays however an anomalous structure of the two PCs of marine origin. A large Cl depletion of the sea-salt aerosol is observed. The time distributions of the concentrations of elements Na and Fe display in all campaigns several peaks of short duration (a few 0.5 days units). The concentration of element S always displays a continuous and generally timevarying background with the superposition of a few peaks. 2002 Published by Elsevier Science B.V.