Twenty-four-hour PM2.5 and PM10 samples were collected simultaneously at a highly trafficked road-side site in Hong Kong every sixth day from October 2004 to September 2005. The mass concentrations of PM2.5, PMlo-2.5 ...Twenty-four-hour PM2.5 and PM10 samples were collected simultaneously at a highly trafficked road-side site in Hong Kong every sixth day from October 2004 to September 2005. The mass concentrations of PM2.5, PMlo-2.5 （defined as PM10 - PM2.5）, organic carbon （OC）, elemental carbon （EC）, water-soluble ions, and up to 25 elements were determined. Investigation of the chemical compositions and potential sources revealed distinct differences between PM2.5 and PM10-2.5. The annual average mass concentrations were 55.5 ＋ 25.5 and 25.9±15.7μg/m^3 for PM2.5 and PM10-2.5, respectively. EC, OM （OM = OC × 1.4）, and ammonium sulfate comprised over -82% of PM2.5, accounting for -29%, -27%, and -25%, respectively, of the PM2.5 mass. Low OC/EC ratios （less than 1） for PM2.5 suggested that fresh diesel-engine exhaust was a major contributor. Seven sources were resolved for PM2.5 by positive matrix factorization （PMF） model, including vehicle emissions （-29%）, secondary inorganic aerosols （-27%）, waste incinera- tor/biomass burning （-23%）, residual oil combustion （-10%）, marine aerosols （-6%）, industrial exhaust （-4%）, and resuspended road dust （-1%）. EC and OM comprised only -19% of PM10-2.5. The average OC/EC ratio of PM10-2.5 was 7.8± 14.2, suggesting that sources other than vehicular exhaust were important contributors. The sources for PM10-2.5 determined by the PMF model included -20% traffic-generated resuspension （e.g., tire dust/brake linear/petrol evaporation）, -17% locally resuspended road dust, -17% marine aerosols, -12% secondary aerosols/field burning, and -11% vehicle emissions.展开更多
PM2.5 and PM2.5 lo concentrations, elemental constituents, and sources in a densely populated coastal industrial area （Trombay, Mumbai） were investigated in 2010 and 2011.The PM2.s and PM2.s lo concentra- tions were...PM2.5 and PM2.5 lo concentrations, elemental constituents, and sources in a densely populated coastal industrial area （Trombay, Mumbai） were investigated in 2010 and 2011.The PM2.s and PM2.s lo concentra- tions were 13.50-71.60 and 22.40-127.78 p^g/m3, respectively. The daily PM25 concentrations exceeded the Indian Central Pollution Control Board limit （60 μg/m3） several days in winter. Of the elements analyzed, Si then Al had the highest concentrations in PM2.5- 10, but black carbon then Si had the highest concentrations in PM2.s. The element concentrations varied widely by season. Al, Ca, Fe, Si, and Ti con- centrations were highest in summer, Cl, Mg, and Na concentrations were highest in the monsoon season, and the other trace metal concentrations in both PM2.5 and PM2.5-10 were highest in winter. The PM2.5 and PM2.5-10 sources were apportioned by positive matrix factorization. PM2.5 and PM2.5-10 had six dominant sources, crustal material （8.7% and 25.3%, respectively）, sea salt spray （6.1% and 15.0%, respectively）, coal/biomass combustion （25.5% and 13.8%, respectively）, fuel oil combustion （19.0% and 11.2%, respectively）, road traffic （ 17.7% and 12.6%, respectively）, and the metal industry （ 10.6% and 7.0%, respectively）. Anthropogenic sources clearly contributed most to PM2.5 but natural sources contributed most to PM2.5-10.展开更多
Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon w...Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon winds to Taiwan. Both PM10 and PM2.5 aerosols collected from northern Taiwan from February 2002 to March 2003 were determined for three heavy metals, namely Pb, Cd and Zn, to characterize the heavy metal compositions between long-range transported and local aerosols and to evaluate their contributions of long-range transport during the northeastern monsoon season. Low Cd/Pb (0.017) and Zn/Pb (1.82) ratios were measured in aerosols during the Asian dust period, in which the sources of ambient aerosols are dominated by long-range transport. By contrast, high Cd/Pb(0.030) and Zn/Pb (3.44) ratios were measured during the summer monsoon season, in which local pollutant emissions dominate the sources of heavy metals. Such characteristic Cd/Pb and Zn/Pb ratios appear to be successfully applied to identify the pollutants originated from the long-range transport or local emissions.展开更多
基金project was supported by Hong Kong Polytechnic University(G-YX3L,G-YF23)the Natural Science Foundation of China (NSFC-21107084)State Key Laboratory of Loess & Quaternary Geology(SKLLQG0804),Chinese Academy of Sciences
文摘Twenty-four-hour PM2.5 and PM10 samples were collected simultaneously at a highly trafficked road-side site in Hong Kong every sixth day from October 2004 to September 2005. The mass concentrations of PM2.5, PMlo-2.5 （defined as PM10 - PM2.5）, organic carbon （OC）, elemental carbon （EC）, water-soluble ions, and up to 25 elements were determined. Investigation of the chemical compositions and potential sources revealed distinct differences between PM2.5 and PM10-2.5. The annual average mass concentrations were 55.5 ＋ 25.5 and 25.9±15.7μg/m^3 for PM2.5 and PM10-2.5, respectively. EC, OM （OM = OC × 1.4）, and ammonium sulfate comprised over -82% of PM2.5, accounting for -29%, -27%, and -25%, respectively, of the PM2.5 mass. Low OC/EC ratios （less than 1） for PM2.5 suggested that fresh diesel-engine exhaust was a major contributor. Seven sources were resolved for PM2.5 by positive matrix factorization （PMF） model, including vehicle emissions （-29%）, secondary inorganic aerosols （-27%）, waste incinera- tor/biomass burning （-23%）, residual oil combustion （-10%）, marine aerosols （-6%）, industrial exhaust （-4%）, and resuspended road dust （-1%）. EC and OM comprised only -19% of PM10-2.5. The average OC/EC ratio of PM10-2.5 was 7.8± 14.2, suggesting that sources other than vehicular exhaust were important contributors. The sources for PM10-2.5 determined by the PMF model included -20% traffic-generated resuspension （e.g., tire dust/brake linear/petrol evaporation）, -17% locally resuspended road dust, -17% marine aerosols, -12% secondary aerosols/field burning, and -11% vehicle emissions.
文摘PM2.5 and PM2.5 lo concentrations, elemental constituents, and sources in a densely populated coastal industrial area （Trombay, Mumbai） were investigated in 2010 and 2011.The PM2.s and PM2.s lo concentra- tions were 13.50-71.60 and 22.40-127.78 p^g/m3, respectively. The daily PM25 concentrations exceeded the Indian Central Pollution Control Board limit （60 μg/m3） several days in winter. Of the elements analyzed, Si then Al had the highest concentrations in PM2.5- 10, but black carbon then Si had the highest concentrations in PM2.s. The element concentrations varied widely by season. Al, Ca, Fe, Si, and Ti con- centrations were highest in summer, Cl, Mg, and Na concentrations were highest in the monsoon season, and the other trace metal concentrations in both PM2.5 and PM2.5-10 were highest in winter. The PM2.5 and PM2.5-10 sources were apportioned by positive matrix factorization. PM2.5 and PM2.5-10 had six dominant sources, crustal material （8.7% and 25.3%, respectively）, sea salt spray （6.1% and 15.0%, respectively）, coal/biomass combustion （25.5% and 13.8%, respectively）, fuel oil combustion （19.0% and 11.2%, respectively）, road traffic （ 17.7% and 12.6%, respectively）, and the metal industry （ 10.6% and 7.0%, respectively）. Anthropogenic sources clearly contributed most to PM2.5 but natural sources contributed most to PM2.5-10.
文摘Along with windblown dust, large quantities of pollutants are annually brought out of the continental by the westerlies in winter and spring; thereafter they are partly subjected to transport by northeastern monsoon winds to Taiwan. Both PM10 and PM2.5 aerosols collected from northern Taiwan from February 2002 to March 2003 were determined for three heavy metals, namely Pb, Cd and Zn, to characterize the heavy metal compositions between long-range transported and local aerosols and to evaluate their contributions of long-range transport during the northeastern monsoon season. Low Cd/Pb (0.017) and Zn/Pb (1.82) ratios were measured in aerosols during the Asian dust period, in which the sources of ambient aerosols are dominated by long-range transport. By contrast, high Cd/Pb(0.030) and Zn/Pb (3.44) ratios were measured during the summer monsoon season, in which local pollutant emissions dominate the sources of heavy metals. Such characteristic Cd/Pb and Zn/Pb ratios appear to be successfully applied to identify the pollutants originated from the long-range transport or local emissions.
