Shih-Han Huang

Concentrations of nano and related ambient air pollutants at a traffic sampling site

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5- 10), fine (PM2.5), ultrafine (PM0.056 - 1) and nano (< 0.056 μm) particle concentrations and size distributions at a traffic sampling site in winter in central Taiwan, from November 2004 to January 2005. Concentrations of metallic elements (Fe, Mg, Cr, Zn, Pb, Cu) and major ion (SO2 - 4; NO- 3; NH+ 4) in particles of various sizes (nano, ultrafine, fine and coarse) were measured. Ambient air particulates generally exhibited a bimodal size distribution in the range 0.056-10 mm. The results show that the concentrations followed the order, Fe-Mg-Cr-Zn-Pb-Cu in PM10, fine, ultrafine and nano-sized particles. Moreover, the data showed that the average metallic elements Fe and Zn have similar concentration distributions: the concentration decreased as the particle size fell in the nano size range.

Characteristic study of ionic species in nano, ultrafine, fine and coarse particle size mode at a traffic sampling site

A micro-orifice uniform deposit impactor (MOUDI) and a nano-MOUDI were used to measure the atmospheric coarse (PM2.5-10), fine (PM2.5), ultrafine (PM0.056 - 1) and nano (< 0.056 μm) particle concentrations at a traffic sampling site in central Taiwan during the winter period from November 2004 to January 2005. Meanwhile, concentrations of major ionic species (Cl-, NO3 −, SO4 2 −, NH4 +, Na+, K+, Ca2+ and Mg2+) were also extracted from various particle size modes (nano, ultrafine, fine and coarse) and analysed by ion chromatography (DIONEX-100). The mass size distribution of ambient suspended particles exhibited two modes. The size ranges of the particles at these two particle size modes were between 1.0 and 1.8 mm and 3.2 and 5.6 mm, respectively. The average mass media aerodynamic diameter (MMAD) of suspended particles was 0.99 mm in this study. In addition, statistical methods, such as correlation coefficient and principal component analysis, were also used to identify the possible pollutant source for various particles size modes (nano, ultrafine, fine and coarse) during the winter months at a traffic sampling site in central Taiwan

Review of atmospheric water-soluble ionic species in Asia during 1998-2001

Anthropogenic acid precursor emissions in Asia are increasing at a significant rate and this is expected to continue for the next several years. This paper comprises of studies that included sulfate, nitrate and ammonium around Asian countries (China, Korea, Japan and Taiwan) in recent years. The paper also provides the water-soluble ionic fine and coarse particulate concentrations in these Asian countries in recent years. Fine and coarse particulates in Taiwan (Kaohsiung and Talchung) and China (Nanjing and Shanghai) were found to have higher sulfate (average 18.68 and 15.75 mg/m3) and nitrate (average 12.77 and 7.71 mg/m3) concentrations than any other Asian country. The average sulfate concentrations for Japan and Korea were 7.31 and 5.84 mg/m3, respectively. The average nitrate concentrations for Japan and Korea were 6.73 and 4.65 mg/m3, respectively during the years 1998-2001. The different sample collection devices, analysis methods and pollutant concentrations are discussed in this study. The purpose of this study is to arrange the atmospheric water-soluble ionic species (SO/2- 4 and NO / - 3) investigations in the Asian region. The data obtained here can also help to understand the sources, concentrations, phase distribution and health impact of atmospheric water-soluble ionic species (SO4 2 - and NO- 3) in other Asian regions.

The concentration, dry deposition, composition study of ambient air particulate and metallic pollutants at a traffic sampling site.

Aerosol samples were collected by total suspended particulate (TSP) and dry deposition plate (downward, upward) from August to November in 2003 in central Taiwan. The particulate metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) were also measured in this study during the summer and autumn periods of 2003. The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 mg/m3) were higher than the night-time period (averaged 542.1 mg/m3). And the downward dry deposition fluxes (averaged 58.12 mg/m2-sec) were about 2.2 times that of upward dry deposition fluxes (averaged 26.37 mg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.54 mg/m2-sec) were also about 2.3 times that of upward dry deposition fluxes (averaged 11.52 mg/m2-sec) in the nighttime period. Moreover, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or night-time period. In addition, the deposition velocity for mass, metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and night-time period were also calculated. In addition, the average TSP composition (mg/g) in the daytime period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 1.73, 0.26, 1.16, 0.28, 0.43 and 0.12 mg/g, respectively. And the average TSP composition in the night-time period of the metallic elements (Fe, Pb, Zn, Cu, Mg and Mn) is 3.02, 0.33, 1.57, 0.41, 0.58 and 0.13 mg/g, respectively at traffic sampling site of central Taiwan.

Atmospheric pollutants study of particles and metallic elements during high wind speed (wind speed >6 m/s) near Taiwan Strait around central Taiwan

The purpose of this study was to characterize metallic elements associated with atmospheric particulate matter in total suspended particulate (TSP), fine particles (particle matter with an aerodynamic diameter of B / 2.5 mm, PM2.5) and coarse particles (particle matter with an aerodynamic diameter of 2.5-10 mm, PM2.5- 10), at high wind speed (wind speed-6 m/s) at Taichung Harbor (TH) and Wuci traffic (WT) in central Taiwan from March to December 2004. The correlation coefficient (R2) between TSP, coarse, fine particulate concentrations versus wind speed at the TH and WT sampling site during high wind speed (-6 m/s) are shown in this study. In addition, the correlation coefficients between TSP, coarse and fine particles of metallic species versus high wind speed were also observed. The results indicated that the correlation coefficient order was TSP-coarse-fine for particles at both sampling sites during high wind speed (-6 m/s) near central Taiwan. In addition, the concentrations of Fe, Zn, Mn, Cu, Pb, Cr, Mg for TSP, coarse and fine particulates were also analysed in this study.

Ambient air particulate dry deposition, concentrations and ionic species study at Taichung Harbor near Taiwan Strait:

The characterization for watersoluble species of dry deposition flux, total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter 2.5 mm, PM2.5), coarse particle (particle matter with aerodynamical diameter 2.5-10 mm, PM2.5 10), and dry deposition velocity were studied at Taichung Harbor sampling sites of central Taiwan during February-August 2004. The average downward dry deposition flux, TSP, PM10 concentrations obtained in Taichung Harbor were about 0.51, 0.3, and 3.4 times more than those values obtained by traffic sampling site in central Taiwan. Average dry deposition velocity for mass, Cl, NO3, SO4 2, Na, NH4, Mg2, and Ca2were 9, 3.8, 0.3, 0.25, 0.46, 0.18, 0.51 and 2.28 cm respectively at the harbor sampling site. In general, average particle mass dry deposition velocity was about 1.8 times more than those values obtained at the traffic sampling site. Chemical analysis, also indicated that three major soluble inorganic species concentrations (sulfate-nitrate-ammonium) accounted for 59.8% and 80.6% of the PM2.5 and PM2.5 10 mass concentrations, respectively at the Taichung Harbor sampling site.

Dry deposition (downward, upward) concentration study of particulates and water-soluble ionic species during daytime, night-time period at the traffic sampling site of Sha-Lu, Taiwan

Ambient suspended particulate (dry deposition, TSP) was collected in the traffic sites Sha-Lu, central Taiwan. In addition, the related water-soluble ionic species (Cl 1/4, NO3 1/4, SO4 2 1/4, Na+, NH4 +, K+, Mg2 +and Ca2+) were analysed and wind speed, wind direction and temperature were also measured in this study. The downward dry deposition fluxes (averaged 54.07 mg/m2-sec) were about twice that of upward dry deposition fluxes (averaged 26.48 mg/m2-sec) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 mg/m2-sec) were also about twice that of upward dry deposition fluxes (averaged 12.11 mg/m2-sec) in the night-time period. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 mg/m3) were higher than in the night-time period (averaged 560.7 mg/m3). The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 mg/m3) were higher than in night-time period (averaged 560.7 mg/m3). As for water-soluble ionic species, the average dry deposition order and velocity for downward ionic species were Cl 1/4 Í-Ca2+Í-NO3 1/4 Í-K+(2.09 cm/sec Í-1.46 cm/sec Í-1.46 cm/sec Í-1.07 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for downward ionic species were NO3 1/4 Í / Cl 1/4 Í / K+Í / Ca2+(2.92 cm/sec Í / 2.74 cm/sec Í / 0.96 cm/sec Í / 0.93 cm/sec) anions during the night-time period. The average dry deposition order and velocity for upward ionic species were Cl 1/4 Í / Ca2+Í / K+Í / Mg2 +(4.69 cm/sec Í / 0.62 cm/sec Í / 0.59 cm/sec Í / 0.55 cm/sec) anions during the daytime period. And the average dry deposition order and velocity for upward ionic species were Cl 1/4 Í-Ca2+Í-Mg2 +Í-K+(1.65 cm/sec Í-0.43 cm/sec Í / 0.37 cm/sec Í / 0.33 cm/sec) anions during the night-time period. The results also indicated that the sodium and chloride concentrations in total suspended particulate were highly positively related, indicating that the sea-salt aerosols were the major contributors for these species at this sampling site of central Taiwan.