This study measured the concentrations of particulates and metallic elements in ambient air by using PS-1 sampler (TSP) at Longjing area. And this study focuses on the collection of ambient air particulates, metallic elements, particulate-bound mercury Hg(p), concentrations. In addition, the sources of ambient pollutants by way of back trajectory analysis are found. Moreover, test mean concentration variance differences for metallic elements (PM, Hg(p), Mn, Fe, Zn, Cr, Cu, and Pb) among the four seasons (spring, summer, autumn and winter) through ANOVA are calculated. The result indicates that the average highest particulate concentration occurred in winter season, and the order was winter > spring > autumn > summer, and the mostly highest average metallic element (Mn, Fe, Zn, Cr, Cu, Pb) concentrations occurred in autumn. Moreover, the mostly average lowest metallic element concentrations occurred in summer. In addition, the above results of backward trajectories that the major particulate pollutants parcel mainly come from northeastern Taiwan. Moreover, when comparing the results of the first half year to that of the second half year, the they indicated that all metallic elements displayed significant differences in concentrations except those of Hg(p), Mn, Fe, Zn. Finally, metallic element Hg(p) is the only one which showed no significant concentration difference from either seasonal variations or half-year observations.

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PM has become an important environmental issue in Taiwan during the past few years. Moreover, electricity increased significantly during the summertime and TTPP generated by coal burning base is the main electricity provider in central Taiwan. Therefore, summer season has become the main research target in this study. The ambient air concentrations of particulate matter PM and PM collected by using VAPS at a mixed characteristic sampling site were studied in central Taiwan. The results indicated that the average daytime PM and PM particulate concentrations were occurred in May and they were 44.75 and 57.77 µg/m in this study. The results also indicated that the average nighttime PM and PM particulate concentrations were occurred in June and they were 38.19 and 45.79 µg/m in this study. The average PM/PM ratios were 0.7 for daytime, nighttime and 24-h sampling periods in the summer for this study. This value was ranked as the lowest ratios when compared to the other seasons in previous study. Noteworthy, the results further indicated that the metallic element Pb has the mean highest concentrations for 24-h, daytime and nighttime sampling periods when compared to those of the other metallic elements (Ni, Cu, Zn and Cd). The average mean highest metallic Pb concentrations in PM10 were 110.7, 203.0 and 207.2 ng/m for 24-h, daytime and nighttime sampling periods in this study. And there were 59.53, 105.2 and 106.6 ng/m for Pb in PM2.5 for 24-h, daytime and nighttime sampling periods, respectively. Moreover, the results further indicated that mean metallic element Pb concentrations on PM and PM were all higher than those of the other elements for 24 h, day and nighttime.

In Asian countries such as China, Malaysia, Pakistan, India, Taiwan, Korea, Japan and Hong Kong, ambient air total suspended particulates and PM concentration data were collected and discussed during the years of 1998-2015 in this study. The aim of the present study was to (1) investigate and collect ambient air total suspended particulates (TSP) and PM concentrations for Asian countries during the past two decades. (2) Discuss, analyze and compare those particulates (TSP and PM) annual concentration distribution trends among those Asian countries during the past two decades. (3) Test the mean concentration differences in TSP and PM among the Asian countries during the past decades. The results indicated that the mean TSP concentration order was shown as China > Malaysia > Pakistan > India > Taiwan > Korea > Japan. In addition, the mean PM concentration order was shown as Vietnam > India > China > Hong Kong > Mongolia > Korea > Taiwan > Japan and the average percentages of PM concentrations for Taiwan, China, Japan, Korea, Hong Kong, Mongolia and Other (India and Vietnam) were 8, 21, 6, 8, 14, 13 and 30%, respectively, during the past two decades. Moreover, t test results revealed that there were significant mean TSP and PM concentration differences for either China or India to any of the countries such as Taiwan, Korea and Japan in Asia during the past two decades for this study. Noteworthy, China and India are both occupied more than 60% of the TSP and PM particulates concentrations out of all the Asia countries. As for Taiwan, the average PM concentration displayed increasing trend in the years of 1998-1999. However, it showed decreasing trend in the years of 2000-2010. As for Korea, the average PM concentrations showed decreasing trend during the years of 2001-2013. Finally, the average PM concentrations for Mongolia displayed increasing trend in the years of 2004-2013.

The concentrations of particulates and metallic elements that were bound to total suspended particulates in ambient air at Long Cyuan Elementary School (LCYES), Lung Ching Elementary School (LCHES) and Long Shan Primary School (LSPS) sampling sites in the Longjing area were measured. Significant difference tests were conducted at LSPS, LCYES and LCHES sites. Finally, carcinogenic and non-carcinogenic risk values for LSPS, LCYES and LCHES sites in the Longjing district were evaluated. The results show that the most average particulate and metallic element concentrations were highest in October, November, January, February, March, April, August, and September The average particulate and metallic element concentrations at LCHES were higher than at the other sampling sites. The Concentration Scatter Diagrams reveal the absence of significant variation among the LSPS, LCYES and LCHES sampling sites in the Longjing district. Therefore, these sampling sites are inferred to have similar emission sources. The children and adults inhalation carcinogenic risks which referenced US EPA method were all within acceptable ranges. Non-carcinogenic risks revealed that all metallic elements considered herein were harmless to human health.