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The study on elemental speciation in atmospheric particulate matter (PM) is important for understanding the formation and origin of pollution and evaluating their toxicity. In this paper, the speciation of iron in atmospheric PM was investigated with extended X-ray absorption fine structure (EXAFS) spectra based on synchrotron radiation. The chemical components of PM can be calculated by regression analysis of EXAFS spectra. This is a non-destructive method. In order to have knowledge of the influence of chemical components on EXAFS spectra, we prepared a series of mixed reference samples, and proved the precision of method is good. The PM samples with different particle sizes and from different sampling sites were collected in Shanghai, China. The chemical components of the samples were calculated by regression analysis of EXAFS spectra. The results show that the iron in all PM samples mainly consist of Fe2O3, Fe3O4 and Fe2(SO4)3, but their proportions are different in different samples. The changes of components among PM samples were observed preliminarily. The concentrations of iron in the samples were determined by proton-induced X-ray emission (PIXE) technique. It is observed that the concentrations of iron in the samples of iron and steel industrial district were much higher than those of other districts, and chemical components were also different from those of others. [ABSTRACT FROM AUTHOR]

The samples of PM2.5 and PM10 inhalable particulate matter had been collected during the period of December 2002–January 2003 at nineteen representative sites of Shanghai urban and suburb area in order to investigate the chemical characterization of aerosol particle in winter. The samples were analyzed to determine the average concentrations for up to twenty elements by means of particle induced X-ray emission (PIXE). It was found that the average elemental concentrations in the urban center are higher than those in the suburb, except for Ti and P. The particulate mass data demonstrate that the ratio range of PM2.5/PM10 is from 0.32 to 0.85 and its average ratio is 0.6. The result of the enrichment factor shows that the inhalable particles may be divided into two categories, i.e., soil elements from the earth crust and anthropogenic pollution elements. It is noticed that toxic or harmful elements such as S, As, Pb, Ni, Mn and Se are enriched mainly in fine particles with diameter less than 2.5 μm. The fingerprints of major pollution sources such as coal (or oil) burning, vehicle exhaust emission and industry are also presented and discussed. [ABSTRACT FROM AUTHOR]

Abstract: Particulate air pollution is associated with respiratory and cardiovascular morbidity and mortality. However, important uncertainties remain in the quantification of extrapulmonary translocation of ultrafine particles into blood circulation. Therefore, the widely used radioiodinated technique was applied to radiolabel polystyrene particles with an average diameter of 56.4 and 202nm, respectively. The extrapulmonary distribution of these particles (3.7×105 Bq/rat) was quantified at 0.5, 2, 24 and 120h after intratracheal instillation in rats. Moreover, we have taken into account the possible involvement of pulmonary inflammation in this process. Rats which received a single intratracheal instillation of free 125I or a single intravenous injection of labeled ultrafine particles served as control. The results indicated that the pulmonary deposition of radioactivity was almost unchanged for both sizes. Only small amounts of radioactivity (1.64–2.49%) were recovered in blood shortly after administration of both types of particle, in healthy rats. However, the extent of particle translocation into the blood of the ultrafine size following the pretreatment with lipopolysaccharides was significantly higher (from 1.96±0.67 to 4.73±0.31%) compared to larger particles (from 2.19±0.77 to 2.21±0.64%). In conclusion, our findings suggest that only a small fraction of intratracheal-instilled ultrafine particles can pass rapidly into systemic circulation, but this translocation is markedly increased following LPS pretreatment. Thus, pulmonary inflammation seems to play a major role in enhancing the extrapulmonary translocation of particles. [Copyright &y& Elsevier]

The stable lead (Pb) isotope ratios and the concentrations of 23 elements, including heavy metals and toxic elements, were measured in the PM10 airborne particle samples collected at seven monitoring sites in Shanghai, China, to evaluate the current elemental compositions and local airborne Pb isotope ratio characteristics. Some source-related samples, such as cement, coal and oil combustion dust, metallurgic dust, vehicle exhaust particles derived from leaded gasoline and unleaded gasoline, and polluted soils were analyzed for their Pb content and isotope ratio and compared to those observed in PM10 samples. Airborne Pb concentration ranged from 167 to 854 ng/m3 in the seven monitored sites with an average of 515 ng/m3 in Shanghai, indicating that a high concentration of Pb remains in the air after the phasing out of leaded gasoline. Lead isotopic compositions in airborne particles (207Pb/206Pb, 0.8608±0.0018; 208Pb/206Pb, 2.105±0.005) are clearly distinct from the vehicle exhaust particles (207Pb/206Pb, 0.8854±0.0075; 208Pb/206Pb, 2.145±0.006), suggesting that the automotive lead is not currently the major component of Pb in the air. By using a binary mixing equation, a source apportionment based on 207Pb/206Pb ratios, indicates that the contribution from automotive emission to the airborne Pb is around 20%. The Pb isotope ratios obtained in the source-related samples confirmed that the major emission sources are metallurgic dust, coal combustion, and cement. [Copyright &y& Elsevier]