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Near-surface atmospheric dust in Changsha city of China was analyzed in terms of morphological and geochemical composition. Morphological and chemical composition of the dust particles were analyzed by environmental scanning electron microscopy coupled with an energy-dispersive X-ray analyzer. Results indicated that the atmospheric dusts were mainly composed of spherule, plate, irregularly shaped and agglomerate, which contains variable sizes and amounts of particles. The dust particles could be categorized into five groups based on their chemical characteristic: Al-, Si-, Ca-, C-rich particles and aggregate. These particles and aggregate could be directly related to nearby polluting activities, such as building construction, traffic emission and coal combustion. The X-ray diffraction results show that the main minerals for atmospheric dust are gypsum, quartz and calcite. Mica, halloysite, montmorillonite, hematite, brushite, zeolite, sepiolite, feldspar, alite, dickite, SiS, Fe(OH)CO, FeSO, CdSO, Pb(NO)O, AlSO(OH), AsOSO, (NH)SO, NHCl, K(NH)·Ca(SO)·HO are also detected in samples. The identification of heavy metals shows that the concentrations of Cr (403.5 mg kg), Cu (126 mg kg), Zn (1541.5 mg kg), Cd (2.5 mg kg) and Pb (348 mg kg) in the atmospheric dust are much higher compared to background value of soil. It indicates that the heavy metal (Cr, Cu, Zn, Cd and Pb) in the atmospheric dust is mainly due to human activities. The identification of main sources of atmospheric dust collected in typical areas can help to control the polluting sources in urban area. [ABSTRACT FROM AUTHOR]

This study was performed to investigate the concentration and the health risk of heavy metals (HMs: Zn, Pb, Cd, Ni, Fe, Mn, Cr and Cu) in size-segregated airborne particulate matter (APM). APM samples were collected into 9 size fractions (> 9.0 μm, 5.8–9.0 μm, 4.7–5.8 μm, 3.3–4.7 μm, 2.1–3.3 μm, 1.1–2.1 μm, 0.7–1.1 μm, 0.4–0.7 μm, < 0.4 μm) by an 8 Stage Non-Viable Cascade Impactor in the campus of Hunan University in Changsha. And then 9 fractions of APM were analyzed for HMs by ICP–OES. The total size-segregated APM concentration in the campus of Hunan University ranged from 120.24 to 271.15 μg/m 3 , and the concentration of HMs in APM was in the range of 38.08–13955.14 ng/m 3 . The health risk of HMs in APM was evaluated by hazard quotient (HQ) and hazard index (HI) and the results showed that dermal contact and ingestion of APM were the major exposure pathways to human health. The HI values of Cd, Mn, Pb and Cr for children and Cd, Mn and Pb for adults exhibited to be higher than 1 indicating that a non-carcinogenic health effect existed in the APM of the campus of Hunan University. The carcinogenic risks of Cd, Ni and Cr were all bellow the safe value. [ABSTRACT FROM AUTHOR]

Abstract: 16 Polycyclic aromatic hydrocarbons (PAHs) in TSP were identified and quantified in samples collected during May and September of 2008, in Changsha, on three different sites: the city environmental protection agency of Changsha (A), the Middle School Attached to Hunan Normal University (B) and Yuhua district (C). The filters contained the particulate matter were extracted with dichloromethane in ultrasonic bath and then analyzed by gas chromatography/mass spectrometry (GC/MS). The total of 16 PAHs mean concentrations of summer at site A, B, C were 32.503ng/m3 , 19.360ng/m3 and 26.784ng/m3, respectively; while the values for autumn at site A, B, C were 24.982ng/m3, 17.088ng/m3 and 15.465ng/m3, respectively. The mean concentrations of PAHs of all samples in A site were 0.57 times higher than those measured at B site, and 0.38 times higher than at C site. The analysis of their distribution amongst the main emission sources was done through the diagnosis of concentration ratios of PAHs, as well as using statistical methods like principal component analysis. The diagnosis results of concentration ratios of PAHs suggested that the major polluting sources in the Changsha region during the studied period were the combustion of fuels, such as diesel oil, gasoline, wood and coal. The statistical analysis separated the 16 compounds studied into 3 and 4 factors for summer and autumn, separately. Factor 1 in summer represents vehicular emissions. Factor 2 represents emissions from the nature gas. Factor 3 represents emissions from combustion. In autumn, vehicle emissions, combustion sources, natural gas and coke oven were the major emissions. [Copyright &y& Elsevier]