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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.

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−, SO42−, 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

This study monitored atmospheric pollutants during high wind speed (7 m s(-1)) at two sampling sites: Taichung Harbor (TH) and Wuci traffic (WT) during March 2004 to January 2005 in central Taiwan. The correlation coefficient (R (2)) between TSP, PM(2.5), PM(2.5-10) particle concentration vs. wind speed at the TH and WT sampling site during high wind speed (7 m s(-1)) were also displayed in this study. In addition, the correlation coefficients between TSP, PM(2.5) and PM(2.5-10) of ionic species vs. high wind speed were also observed. The results indicated that the correlation coefficient order was TSPPM(2.5-10)PM(2.5) for particle at both sampling sites near Taiwan strait. In addition, the concentration of Cl(-), NO(3) (-), SO(4) (2-), NH(4) (+), Mg(2+), Ca(2+) and Na(+) were also analyzed in this study.

Air aerosol samples for TSP (total suspended particulate), coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)), fine particulate (particle matter with aerodynamical diameter2.5 microm, PM(2.5)) and metallic elements were collected during March 2004 to January 2005 at TH (Taichung Harbor) in central Taiwan. The seasonal variation average concentration of TSP (total suspended particulate), coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)) and fine particulate (particle matter with aerodynamical diameter2.5 microm, PM(2.5)) were in the range 132-171.1 microg m(-3) and 43-49.5 microg m(-3), respectively. Seasonal variation of metallic elements Cu, Mn, Zn and Fe in the TSP (total suspended particulate) shows that higher concentration was observed during spring. Seasonal variation of metallic elements Pb, Cr and Mg in the TSP (total suspended particulate) shows that higher concentration was observed during winter. The average metallic element TSP (total suspended particulate) concentration order was FeZnMgCuCrMnPb in spring. In addition, at the TH sampling site, the average concentration variation of TSP (total suspended particulate) displayed the following order: springwinterautumnsummer. However, the average concentration variation of coarse particulate (particle matter with aerodynamical diameter 2.5-10 microm, PM(2.5-10)) displayed the following order: springwintersummerautumn. Finally, the average concentration variations of fine particulate (particle matter with aerodynamical diameter2.5 microm, PM(2.5)) were in the following order: winterspringsummerautumn at the TH sample site.

The concentrations of total suspended particulate (TSP), fine particles PM(2.5) (with aerodynamic diameter