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Fine (PM(2.5)) and coarse (PM(2.5-10)) particulate concentrations of ambient air polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously from February 2004 to January 2005 at the Taichung Harbor (TH) sampling site near Taiwan of central Taiwan. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters; the collected sample was Soxhlet extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24 h, and then the extracts were analyzed by gas chromatography-mass spectrometry (GC-MS). The results indicated that vehicle emissions, coal combustion, incomplete combustion and pyrolysis of fuel and oil burning were the main source of PAHs near Taiwan Strait of central Taiwan. Diagnostic ratios and principal component analysis (PCA) were also used to characterize and identify PAHs emission sources in this study.

Fine (PM(2.5)) and Coarse (PM(2.5-10)) particulates concentrations of ambient air particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously from February 2004 to January 2005 at the Taichung Harbor (TH) sampling site near Taiwan of central Taiwan. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters, the collected sample used soxhlet analytical method extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24h, and then the extracts were subjected to gas chromatography-mass spectrometric (GC-MS) analysis. The results indicated that vehicle emissions, coal combustion, incomplete combustion and pyrolysis of fuel and oil burning were the main source of PAHs near Taiwan Strait of central Taiwan. Diagnostic ratio and principal component analysis (PCA) were also used to characterize and identify PAHs emission source in this study.

The concentrations of ambient air polycyclic aromatic hydrocarbons were measured in a farm area (Tunghai University Pastureland) between August 2001 and April 2002 in central Taiwan, Taichung. Particle-bound polycyclic aromatic hydrocarbons (PAHs) were collected on quartz filters, the collected sample was extracted with a dichloromethane (DCM)/n-hexane mixture (50/50, v/v) for 24 h, and then the extracts were subjected to gas chromatography-mass spectrometric analysis. The PM2.5 (fine particulate) and PM2.5-10 (coarse particulate) total PAHs concentrations at the Tunghai University Pastureland sampling site were found to be 180.62 ngm(-3) and 164.98 ngm(-3), respectively. In general, the concentrations of polycyclic aromatic hydrocarbons were higher in spring and winter than those of summer and autumn for either PM2.5 or PM2.5-10 in Pastureland in central Taiwan. Moreover, coarse particulates are the dominant species during the dust storm season (March and April) in central Taiwan.

Fine (PM2.5) and coarse (PM(2.5-10)) particulates were collected simultaneously by using a versatile air pollutant system at a traffic sampling site during daytime and nighttime sampling periods during August 2003 to March 2004. A flame atomic absorption spectrophotometer coupled with hollow cathode lamps were used for chemical analysis. Enrichment factor and principal component analysis were used to compare chemical components and to find the possible emission sources at this traffic sampling site. The variation of metallic element concentrations on fine and coarse particulates during daytime and nighttime was also discussed in this study. Soil dust, traffic exhaust, marine salt and anthropogenic activities were the major pollutant sources at the traffic sampling site in central Taiwan.

The concentrations of ambient air polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in an industrial area (Taichung Industrial Park, TIP) and suburban area (Tunghai University, THU) in central Taiwan, Taichung. A total of samples were collected simultaneously at the two sites between August 2002 and March 2003. Particle-bound PAHs (p-PAHs) were collected on quartz filters and gas-phase PAHs (g-PAHs) on glass cartridges using polyurethane foam sampler, respectively. Both types of samples were extracted with dichloromethane/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography/mass spectrometric analysis. Moreover, the roadside dust particle PAHs composition were also collected and analyzed at TIP, THU and traffic road sampling sites. The five main road lines in Taichung City were selected as traffic road sampling sites. Correlation studies between PAHs concentrations and meteorological parameters were revealed that temperature has greater effects (P>0.6) than other meteorological parameters such as wind speed, relative humidity and atmospheric pressure on g-PAHs and p-PAHs. PAHs sources were resolved by using principal component analysis and diagnostic ratios. The major sources of PAHs were combustion, traffic vehicle exhaust (diesel and gasoline engine), incinerator and industrial stationary sources at both sampling sites in central Taiwan.

Atmospheric aerosol particles and metallic concentrations were monitored at the Experimental Farm of Tunghai University (EFTU) sampling site in this study. Total suspended particulate matter (TSP) was collected by using a PS-1 sampler at the farm-sampling site, in central Taiwan, from July 2001 to April 2002. At the same time, PM(2.5) and PM(2.5-10) were also measured with a Universal sampler from January 2002 to April 2002. Only subjects with the most complete data records on TSP sampling (N=43) and PM(10) sampling (N=23) were used in this analysis. Taichung Industrial Park, Taichung Kang Road (traffic) and a Hospital Incinerator surround the Experimental Farm of Tunghai University. Atmospheric concentrations of metallic elements were analyzed by a flame atomic absorption spectrophotometer (AA-680/G). The results indicated that the metallic elements Mg, Cu and Mn were the largest components in the TSP fraction; the metallic elements Fe and Cd were the largest composition in the PM(2.5-10) fraction; however, the metallic elements Pb, Zn, Cr and Ni were the largest abundance in the PM(2.5) fraction. The atmospheric metallic elements in the TSP, PM(2.5) and PM(2.5-10) fractions came different emission sources, such as soil, traffic, industry and resuspended particles.

Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over the bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there are more than 20,000 aftershocks following the Taiwan Chi-Chi Earthquake within 3 months. Thus, the mass concentration of particles with aerodynamic diameters smaller than 2.5 microm (PM2.5) and PM2.5-10 was also collected then compared with the total mass concentration of suspended particles (TSP) in this study. The average TSP, PM2.5-10, and PM2.5 concentrations are 106, 24.6, and 58.0 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 69.6 and 127 microg/ m3, respectively. In addition, statistical analysis of the PM10 data from this study and EPA in 1999 yielded a Tstatistic of 0.147, which is smaller than t(0.975,18) = 2.101. It is indicated that there was no significant difference. So, the PM10 concentrations measured after Taiwan Chi-Chi Earthquake in this study were also greater than those data previously obtained from Taiwan EPA in the same region of this area. The relationships between TSP, PM10, PM2.5-10, and PM2.5 particle concentrations and wind speed (R2) are .77, .59, .58, .58, respectively. And the ratios of PM2.5/PM25-10, PM2.5/PM10, and PM10/TSP are 221%, 67.2%, 58.0%, respectively. The average ratios of PM2.5/PM2.5-10 and PM2.5/PM10 increase by about 120% and 17%. It indicated that the fine-particles concentration increases compared to the coarse-particles concentration after 921 Taiwan Chi-Chi Earthquake. And the proposed reasons are that local motor vehicle emissions combined the fine particles transported from the Chi-Chi epicenter. More importantly, the wind direction was mainly blown from southeastern part. These two main factors enhance the fine-particles concentration in this area.

Ambient particle concentration was taken on the traffic sampling site over the Chung-Chi Road over bridge (CCROB) in front of Hungkuang Institute of Technology (HKIT). The sampling time was from August 1999 to December 1999. During the sampling period, Taiwan's biggest earthquake in more than a century registered 7.3 on the Richter scale (Taiwan Chi-Chi Earthquake). Besides, there were more than 20,000 aftershocks that followed the Taiwan Chi-Chi Earthquake within three months. Thus, the PM2.5, PM(2.5-10) particle concentrations were also collected then and compared with total suspended particle (TSP) in this study. The average PM(2.5-10), PM2.5 and TSP concentrations are 24.6, 58.0 and 106 microg/m3, respectively, after the Taiwan Chi-Chi Earthquake. The average TSP concentrations before and after Taiwan Chi-Chi Earthquake were 70 and 127 microg/m3, respectively. It is clearly shown that the average concentration of TSP after Taiwan Chi-Chi Earthquake was about 1.8 times as that of TSP concentration before Taiwan Chi-Chi Earthquake in the traffic site of central Taiwan. And the ratios of PM2.5/PM(2.5-10), PM2.5/PM10 and PM2.5/TSP are 2.2%, 67.2%, 38.9%, respectively. The results also indicated about Chi-Chi fine particle concentration (PM25) and the TSP increases in the traffic site of central Taiwan after Taiwan Chi-Chi Earthquake.

Aerosol samples for PM2.5, PM(2.5-10) and TSP were collected from June to September 1998 and from February to March 1999 in central Taiwan. Ion chromatography was used to analyze the acidic anions: sulfate, nitrate and chloride in the Universal samples. The ratios of fine particle concentrations to coarse particle concentrations displayed that the fine particle concentrations are almost greater than that of coarse particle concentrations in Taichung area. The average concentrations of PM2.5, PM(2.5-10) and TSP in urban sites are higher than in suburban and rural sites at both daytime and night-time. Chloride dominated in the coarse mode in daytime and in fine mode in night-time. Nitrate can be found in both the coarse and fine modes. Sulfate dominated in fine mode in both daytime and night-time.

Daily average concentrations of fine and coarse particulates, and TSP samples have been measured simultaneously at daytime and night-time periods by using Universal and PS-1 sampler in a suburban area of central Taiwan from June to August 1998. The samples were analyzed by atomic absorption spectrometry to determine the fine and coarse particulate concentrations of metallic elements (Ca, Fe, Mn, Pb, Cu, Zn and Cr). The concentration of PM2.5 and TSP showed a decreased trend for the daytime period. The fine particle concentrations were about two times as that of coarse particulate concentrations. The averaged fine particulate concentrations at daytime are higher than at night-time. Ca and Fe were mostly in the coarse particulate mode. The correlation coefficients were 0.63 and 0.69 for elements Ca and Fe in the coarse particle mode for day and night periods. Pb showed a similar distribution ratio with Mn for the fine to coarse particle ratios at both day and night period. Pb and Mn are highly correlated for the day (R = 0.78) and night period (R = 0.61) at particle size <2.5 microm. Cu and Zn were mainly in fine particles at both day and night period. Fe and Ca consist of the major parts of all the elements. Elemental Mn is the lowest among the rest of the heavy metals.

Aerosol samples for PM2.5 (particulate matter with aerodynamic diameters less than 2.5 microns), PM2.5-10 (particulate matter with aerodynamic diameters between 2.5 and 10 microns) and TSP were collected from June to September 1998 at THU (suburban) and HKIT (rural) sites in central Taiwan. The ratios of PM2.5/PM10 averaged 0.70 for the daytime and 0.63 for the nighttime at THU, respectively. At HKIT, the PM2.5/PM10 ratios averaged 0.56 for the daytime and 0.72 in the nighttime, respectively. These results indicated that the PM2.5 concentrations contribute the majority of the PM10 concentration and PM10 concentrations contribute the majority of the TSP at both sites. The averaged PM2.5 concentrations at THU are higher than those measured at HKIT during the daytime period. However, the average PM2.5-10 concentrations in THU are lower than those measured at HKIT during nighttime. The samples collected were also analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Zn, Cu, Mn and Cr. Meanwhile ion chromatography was used to analyze for the water-soluble ions: sulphate, nitrate and chloride in the Universal samples. The concentrations of heavy metals in PM10 during daytime were all higher than nighttime at THU. However, the averaged concentrations of metal elements in PM10 during day and night period were distributed irregularly at HKIT. The results indicated that for metal elements collected at HKIT have different emission sources. The concentrations of metal elements during daytime in PM10 at THU were generally higher than HKIT. The phenomena owing to the averaged PM2.5 particle concentrations at THU (suburban) were higher than those measured at HKIT (rural) and PM2.5 occupied the major portions of PM10 for both sites during the day period. For anion species, there are no significant differences between day and night period in PM10 concentrations at both suburban and rural sites.

The total suspended particle (TSP), PM2.5-10 (aerodynamic diameter less than 10 microns) and PM2.5 concentration (aerodynamic diameter less than 2.5 microns) concentrations were sampled by PS-1 and Universal sampler on the roof (25 m) of the Medical and Engineering Building in the campus of Hungkuang Institute of Technology (HKIT) which is located at a height of 500 m on Da Du Mountain. The results indicated that average TSP, PM2.5-10 and PM2.5 concentrations are 0.42, 0.34 and 0.019 mg/m3 in the day time, respectively and are 0.32, 0.26 and 0.017 mg/m3 in the night time, respectively. The ratios of PM2.5-10/TSP were from 76% to 85% and from 50% to 91% for day and night period, respectively. It indicated that the major composition in the total suspended particles was PM2.5-10 in the rural site. The relationship between TSP and PM2.5-10 is TSP = 1.16PM2.5-10 + 0.027 and TSP = 1.01 PM2.5-10 + 0.058 in the day and night time, respectively. The correlation coefficient (R2) is 0.98 and 0.97 for day and night period, respectively. The relationship between PM2.5-10 and PM2.5 is PM2.5 = 0.0005PM2.5-10 + 0.019 and PM2.5 = 0.037PM2.5-10 + 0.0076 in the day and night period, respectively. The correlation coefficient (R2) is 3E-5 and 0.67 for day and night period, respectively. The relationships between TSP, PM2.5-10, PM2.5 particle concentrations and wind speed (R2) in the day time are 0.71, 0.64, 0.43, respectively and are 0.83, 0.79, 0.57, respectively in the night time. The proposed reasons are that there are more activities caused by people (students) and natural living animals which absorbed some of the particles during the day time. Thus, the correlation coefficients for the night time are better than those of day time. The particle size distributions are both bimodel in the day and night time. The major peaks in the day time appear in the particle diameter between 0.031-0.056 micron and 3.16-5.62 microns in the day period and appear between 0.017-0.031 micron and 1.78-3.16 microns in the night period. The results indicate that the particle size distribution in the day time tends to be of larger particle size mode than the night time.