Characterization of particulate matter sources in an urban environment

Abstract

Daily time series measurements of elements or compounds are widely used to apportion the contribution of specific sources of particulate matter concentration in the atmosphere. We present results obtained for the urban area of Genoa (Italy) based on several hundred of PM10, PM2.5 and PM1 daily samples collected in sites with different geo-morphological and urbanization characteristics. Elemental concentrations of Na to Pb were obtained through Energy Dispersive X-Ray Fluorescence (ED-XRF), and the contributions of specific sources of particulate matter (PM) concentration were apportioned through Positive Matrix Factorization (PMF). By sampling at different sites we were able to obtain, in each PM fraction, the average and stable values for the tracers of specific sources, in particular traffic (Cu, Zn, Pb) and heavy oil combustion (V, Ni). We could also identify and quote the contamination of anthropogenic PM in "natural" sources (sea, soil dust). Sampling at several sites in the same urban area allowed us to resolve local characteristics as well as to quote average values. IntroductionIn recent years, atmospheric aerosols have been studied extensively (Charlson et al., 1992;Harrison et al., 2001;Satheesh and Moorthy, 2005 , 2002a,b;Stieb et al., 2002;Fernandez et al., 2003).Up to now, PM concentrations have been routinely monitored. However, this level of monitoring is insufficient and a measurement of the elemental and chemical composition of PM is recommended in order to achieve a more complete picture. Indeed concentration limits have been set in Europe for some toxic elements (Pb, Ni, Cd, Hg; see the recent European Directive 2004/107/CE). Element and/or compound measurements can also help to trace specific emission patterns. Thus, the knowledge of the chemical composition of particulate matter can be used to evaluate the impacts of the various pollution sources on air quality. Several "source apportionment" strategies have been developed; receptor models (Gordon, 1988) are presently considered the most effective approach. These models usually provide three pieces of information: the number of (major) sources of particulate matter, the source profiles and the mass contribution of each source to total PM. These models single out groups of elements with correlated concentration trends, which

Coarse Particulate Matter Apportionment around a Steel Smelter Plant

“…The latter value is still 47% higher than the town average of 1.14 g ⅐ m Ϫ3 . 22 The same trend can be observed for Mn concentration (40 g ⅐ m Ϫ3 in F-ON and 24 g ⅐ m Ϫ3 in F-OFF; Figure 2). Furthermore, in the F-ON dataset, Fe daily concentration reached 30 g ⅐ m Ϫ3 ; whereas during F-OFF, the maximum Fe concentration was 13 g ⅐ m Ϫ3 .…”

“…This is a clear track of the smelter activity because in all of the other districts of the town, and also during F-OFF, S is the element (among those detected by ED-XRF) with the highest concentration. 22 The average Fe concentration (4.48 g ⅐ m Ϫ3 ) was approximately 4 times the town mean value in F-ON and it decreased to 1.68 g ⅐ m Ϫ3 after plant closure (F-OFF). The latter value is still 47% higher than the town average of 1.14 g ⅐ m Ϫ3 .…”

Anthropogenic and natural constituents in particulate matter in the Netherlands

“…Important information on the origin of particulate matter can be obtained through chemical analysis to establish its composition Viana et al, 2008;Sillanpää et al, 2006;Salvador et al, 2007;Mazzei et al, 2008;Almeida et al, 2007). Many components can be used as tracers for specific sources.…”

Assessment of atmospheric trace element concentrations by lichen-bag near an oil/gas pre-treatment plant in the Agri Valley (southern Italy)

“…The origin of this last element, especially in the same component as Cr, may be related to industrial emissions (Bari et al, 2009;Mazzei et al, 2008;Negral et al, 2008). Therefore, PC 1−12 months identifies contributions of natural sources associated with those coming from traffic and coal combustion processes.…”

“…Frequently, the anthropogenic sources are more significant than the natural ones for most of the toxic trace elements (e.g. Pb and Cd) (Caggiano et al, 2010;Mazzei et al, 2008).…”