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Abstract: Positive matrix factorization (PMF) was applied to identify the types of PM2.5 sources and corresponding mass contributions to PM2.5 mass concentrations using PM2.5 measurements obtained from Dec. 2007 to Oct. 2008 in Jinan, which is a highly polluted city in China. The reconstructed mass concentrations from six sources matched the observations, and the resolved sources constituted 98.91% of the PM2.5 mass concentrations. Secondary sources, the major source contributor, accounted for 55.15% of PM2.5 mass concentration, while several other sources, including coal burning (20.98%), soil dust (9.30%), motor vehicles (6.06%), biomass burning (4.55%), and industry (2.87%), contributed a total of 43.76%. The non-carcinogenic risk estimates showed the elemental risk for Mn, Co, S and Cr were high, with values larger than 0.1 being observed for the three groups. The total elemental risk in Jinan for the three groups was higher than 1, and the largest risk was present for children between the age of 6–12 followed by that for children between 2 and 6 years of age, indicating that citizens in Jinan, particularly children, faced more serious potential non-carcinogenic health risks. [Copyright &y& Elsevier]

Abstract: To better understand secondary aerosol pollution and potential source regions, semi-continuous measurement of water-soluble ions in PM2.5 was performed from December 2007 to October 2008 in Jinan, the capital of Shandong Province. The data was analyzed with the aid of backward trajectory cluster analysis in conjunction with redistributed concentration field (RCF) model and principal component analysis (PCA). , and were the most abundant ionic species with annual mean concentrations (±standard deviations) of 38.33 (±26.20), 15.77 (±12.06) and 21.26 (±16.28) μg m−3, respectively, which are among the highest levels reported in the literatures in the world. Well-defined seasonal and diurnal patterns of , and were observed. The fine sulfate and nitrate oxidation ratios (SOR and NOR) were much higher in summer (SOR: 0.47 ± 0.13; NOR: 0.28 ± 0.03) than those in other seasons (SOR: 0.17–0.30; NOR: 0.12–0.14), indicating more extensive formations of and in summer. The most frequent air masses connected with high concentrations of , and originated from Shandong Province in spring, autumn and winter, while from the Yellow Sea in summer, and then slowly traveled in Shandong Province to Jinan. RCF model indicated that Shandong Province was the main potential source region for and and other potential source regions were also identified including the provinces of Hebei, Henan, Anhui and Jiangsu and the Yellow Sea. Principal component analysis indicated that the major sources contributing to PM2.5 pollution were secondary aerosols, coal/biomass burnings and traffic emissions. [Copyright &y& Elsevier]