Search

Among non-exhaust emissions, road dust resuspension represents a rather important contribution to particulate matter in urban areas. This study aimed to achieve a chemical characterisation of road dust particulate matter (PM10) on two motorway sections, one rural and one urban, and to explore the related health and ecotoxicological risks. Measured PM10 dust loadings reached very low levels (0.66–1.49 mg m-2) compared to equivalent studies in other road environments in Portugal and other countries. Emission factors ranged from 33 to 62 mg veh−1 km−1. The carbonaceous content represented 14% of the total PM10 mass, whereas the highest contribution to the mass was given by mineral matter. Elements such as Si, Al, Ca, Fe and K accounted for almost three quarters of the total element mass for all samples, whilst Cu and Zn, mostly associated with brake and tyre wear, were the most enriched elements in relation to the soil composition. Nonetheless, Ti and Zr presented the highest non-carcinogenic risks for human health. Despite the low amounts of particulate matter in the aqueous solution, the ecotoxicological screening with the Aliivibrio fisheri bioluminescence inhibition bioassay allowed to classify the samples as toxic. [ABSTRACT FROM AUTHOR]

Wastes from electrical and electronic equipment (WEEE) are disposed and dismantled in recycling plants where chemical composition of particulate matter (PM) is different from all the other working places. A first identification of airborne contaminants, associated with size-segregated particles in the fine (aerodynamic diameter < 2.5 µm) and coarse (aerodynamic diameter in the range 2.5–10 µm) fractions, sampled in two sectors of a WEEE facility, was performed. In the two areas of the plant, disassembly and shredding processes produced large amounts of dust, causing mass concentrations of airborne particles particularly high when activities intensified. Analyses of Na, Mg, Al, Si, P, S, Cl, K, Ca, Ti, V, Cr, Mn, Fe, Ni, Cu, Zn, Ga, As, Se, Br, Rb, Sr, Y, Zr, Mo, Ba, and Pb were performed on PM samples collected by a streaker sampler. PM was collected with hourly and 30-min time resolution in the two sectors of the plant for three consecutive days, night and day. Organic substances belonging to the classes of polycyclic aromatic hydrocarbons (PAHs) and their oxy- and nitro- derivatives (oxy-PAHs and nitro-PAHs), organophosphorus compounds (OPEs), polyfluoralkyl substances (PFASs), and novel-brominated flame retardants (BFRs) were extracted and identified in PM samples collected by PM10 impactors. Particle sampling period for organic analyses was 4 h per day in the same three days, in each sector of the plant, during the working hours. High time resolution records of elemental composition were useful for highlighting the elements strongly depending on the productive process. During working hours, Pb and Ba concentrations reached higher levels and drastically decreased during the night. Their distribution in the coarse and fine fractions consistently increased and decreased, meaning that both fractions were linked to the working activity. Si, as main component of glass, was the most abundant element at both the areas. Though all the elements were below the permissible exposure limits recommended by Occupational Safety and Health Administration (OSHA's PELs), the concentration of Pb was significantly high, especially at the shredding zone (21.9 µg/m3). The major organic constituents, among the classes of compounds investigated, were organophosphorus compounds (OPEs), especially in the coarse fraction of PM. In particular, triphenylphosphate (TPhP), deriving from computer video display units, was the most abundant organic compound. Interestingly, phenanthrene contributed to 60% of the total polycyclic aromatic hydrocarbons (PAHs), at both the sampling sites. Airborne plastic dust can be a source of PAHs. Products made of polyethylene recycled from post-commercial waste contain high concentrations of phenanthrene, present as impurities. The present study represents a preliminary investigation on WEEE plants airborne PM composition and additional research is necessary to confirm the data, but it is worth developing a method, as high particle concentrations, together with absorbed genotoxins, could constitute an occupational health risk. [ABSTRACT FROM AUTHOR]

Introduction: The concentrations of trace metals, ionic species, and carbonaceous components in PM (particulate matter with aerodynamic diameters smaller than 10 µm) were measured from samples collected near an industrial complex, primarily composed of cement plants, in southeastern Spain, from September 2005 to August 2006. Materials and methods: Positive matrix factorization and conditional probability function were applied to this data set to identify different types of sources. Results: Six significant sources were identified: crustal matter, traffic, aged sea salt, industrial emissions, secondary aerosol, and sea salt. The difficulty of separating anthropogenic sources from those of natural origin is highlighted in this study; in particular, the crustal source can be connected with both natural (African outbreaks, wind resuspension) and man-made emissions, like fugitive emissions in an industrial environment. [ABSTRACT FROM AUTHOR]

Nowadays, high-time resolved aerosol studies are mandatory to better understand atmospheric processes, such as formation, removal, transport, deposition or chemical reactions. This work focuses on PM10 physical and chemical characterisation with high-time resolution: elements (from Na to Pb), ions and OC/EC fractions concentration were determined during two weeks in summer and two in winter 2006 with 4-hours resolution. Further measurements aimed at hourly elemental characterisation of fine and coarse fractions and at the determination of particles number concentration in the 0.25–32 μm size range in 31 bins. The chemical mass closure was carried out in both seasons, enhancing intra-day differences in PM10 composition. In Milan, the highest contribution came from organic matter (34% and 33% in summer and winter, respectively); other important contributors were secondary inorganic compounds (16% and 24% in summer and winter, respectively) and, in summer, crustal matter (14%). Temporal trends showed strong variations in PM10 composition during contiguous time-slots and diurnal variations in different components contribution were identified. Moreover, peculiar phenomena, which would have hardly been detected with 24-hours samplings, were evidenced. Particles removal due to precipitations, aerosol local production and long range transport were studied in detail. [ABSTRACT FROM AUTHOR]

We describe the results of an aerosol sampling campaign performed in 1999 in the medium-size industrial town of La Spezia, in the Northwest of Italy. We used two-stage continuous streaker samplers in three different sites and periods of the year. This kind of samplers allows the separation of the PM10 and PM2.2 fractions of the particulate matter. Moreover, the hourly resolution in the aerosol collection is particularly useful in an urban environment where, typically, many pollution sources with fast variations are present. Up to 1700 samples have been analysed by Particle Induced X-ray Emission (PIXE) at the INFN accelerator facility in Florence, obtaining hourly concentration for about 20 elements from Na to Pb, with a sensitivity ranging from below 1 to about 10 ng m-3. The total hourly aerosol mass has been estimated with an optical analysis of the same samples performed (before the PIXE analysis) by an equipment designed and mounted in Genoa. An extensive statistical analysis of the data included standard and Absolute Principal Component Factor Analysis (PCFA and APCFA) to deduce the composition and the weight of the major aerosol sources in both fractions. Thorough different statistical approaches, we generally resolved contributions from vehicle emission, fossil fuel combustion, soil-road dust and sea salt aerosol. [ABSTRACT FROM AUTHOR]

An extensive investigation is in progress aiming at the characterisation of the air particulate composition in Florence. For our investigation, we use the external PIXE-PIGE beam facility of the I.N.F.N. Van de Graaff accelerator at the Physics Department of the Florence University. In order to gather information on both the longer- and shorter-time trends of the aerosol elemental composition, we are analysing both long temporal series (about 1 year) of 24-h Millipore filters collected by the health authorities in 3 different sites, and filters collected simultaneously in two of the above sites for about one month, by two streakers with one-hour resolution, providing size fractionation between particle size smaller than 2.5 µm and from 2.5 µm to 10 µm. The streakers sampling period includes two days during which the Municipality of Florence has banned the circulation of non-catalytic cars, due to the increase of NO2 above the "recommended safety values". We present here the first obtained results for the sampling site located near a heavy traffic road. [ABSTRACT FROM AUTHOR]

There are an increasing number of articles in the scientific literature dealing with the study of atmospheric aerosol because it has negative impacts on human health, atmospheric visibility and a role in the radiative forcing. Particle-induced X-ray emission (PIXE) has been used since its birth for the study of the aerosol composition, and for a long time, it has been the dominating technique for its elemental analysis. However, nowadays other competitive techniques play a dominant role, such as inductively coupled plasma–mass/atomic emission spectroscopy, energy-dispersive X-ray fluorescence and synchrotron radiation. Therefore, it is important to find specific applications where it can give unique information or the final results in a far simpler way. Furthermore, a proper experimental setup must be used to fully exploit the potential of PIXE. Thanks to the capability of detecting all the crustal elements, PIXE analyses are unrivaled in the study of mineral dust. Among the detectable elements, there are also important markers of anthropogenic sources, which allow effective source apportionment studies in polluted urban environments using multivariate methods. Examples regarding recent monitoring campaigns will be presented to show how PIXE is still on the cutting edge for the study of particulate matter. [ABSTRACT FROM AUTHOR]