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This study assessed the impact on air quality and health risk by long-range transported (LRT) PM2.5-10- and PM2.5-bound metals and PAHs in Taipei City, Taiwan. Several methods with receptor aerosol measurements were used to quantify the effect of LRT. The hybrid single particle lagrangian integrated trajectory model (HYSPLIT) was used in conjunction with the potential source contribution function (PSCF) to distinguish the LRT aerosols. By using a general linear model (GLM) with a marginal mean and positive matrix fraction (PMF), this study also evaluated the annual increased level of LRT (AIRLRT) for each source contribution to the concentration and the resultant health risk of particle-bound metals and polycyclic aromatic hydrocarbons (PAHs). The LRT influenced fine-sized metals and PAHs rather than coarse-sized ones. We found that the level of PM2.5-bound toxic metals (Pb, Cd, and As) and PAHs (Benzo[a]pyrene and dibenzo[a,e]pyrene) could increase by 90% under the influence of LRT in 2014, while an AIRLRT value of 25% for the PM2.5 mass concentration was observed. Overall, the excess cancer risk (ECR) resulting from PM2.5-bound metal and PAH exposures was 6.40 × 10−5 in relation to coal combustions (20.7%), traffic-related emissions (59.7%) and re-suspended aerosols (19.6%). Among these contributors, LRT-related metals and PAHs in PM2.5 accounted for 51% of the total ECR.

We investigated spatial and season variations in particle-bound PAH concentrations, identified their potential sources and estimated resultant health risk of activate toxicity pathways in a residential area near coal-fired power and steelmaking plants. Both atmospheric PM2.5 and PM10 samples (n = 94) were simultaneously collected for summer and winter in the Wuqi and Shalu districts of Taichung City, central Taiwan. The principal component analysis (PCA) measure was used to evaluate the sources of particle-bound PAHs. The health risk of PAHs-activated toxicity pathways was estimated through a probabilistic model in cooperation with high-throughput screening (HTS) in vitro assays and measurement data for children and adults. No spatial difference, but significant seasonal variation, in PAH concentrations for PM2.5 (summer = 1.7 ng m−3 and winter = 4.7 ng m−3) and PM10 (summer = 2.1 ng m−3 and winter = 4.8 ng m−3) between two sites was observed, where both sites shared the similar PAH patterns in congener concentrations. PAH contents in the fine mode (PM2.5) of ambient particles are predominant while coarse mode (PM2.5–10) PAHs is negligible. Children with particle-bound PAH exposures have a relatively high health risk of aryl hydrocarbon receptor (AhR)-mediated adverse outcomes than adults, in particular in the winter period, while the activations of Nrf2 and p53 pathways are insignificant. Vehicle emission (67.1%), unburned petroleum (15.0%), steel industry and stationary emission (6.1%), and oil combustion + cooking oil fume (5.6%) associated with PM2.5-bound PAHs were apportioned. The emission from the Taichung coal-fired power plant is rarely attributable to particle-bound PAHs of the study area based on results of spatiotemporal variation of PAHs, wind direction, and source apportionment.

This study investigates PM 2.5 -bound PAHs for rural sites (Dacheng and Fangyuan) positioned close to heavy air-polluting industries in Changhua County, central Taiwan. A total of 113 PM 2.5 samples with 22 PAHs collected from 2014 to 2015 were analyzed, and Positive Matrix Factorization (PMF) and diagnostic ratios of PAHs were applied to quantify potential PAH sources. The influences of local and regional sources were also explored using the conditional probability function (CPF) and potential source contribution function (PSCF) with PMF-modeled results, respectively. Annual mean concentrations of total PAHs were 2.91 ± 1.34 and 3.04 ± 1.40 ng/m 3 for Dacheng and Fangyuan, respectively, and their corresponding BaP eq were measured at 0.534 ± 0.255 and 0.563 ± 0.273 ng/m 3 in concentration. Seasonal variations with higher PAHs found for the winter than for the spring and summer were observed for both sites. The lifetime excess cancer risk (ECR) from inhalation exposure to PAHs was recorded as 4.7 × 10 −5 overall. Potential sources of PM 2.5 -bound PAHs include unburned petroleum and traffic emissions (42%), steel industry and coal combustion (31%), and petroleum and oil burning (27%), and unburned petroleum and traffic emission could contribute the highest ECR (2.4 × 10 −5 ). The CPF results show that directional apportionment patterns were consistent with the actual locations of local PAH sources. The PSCF results indicate that mainly northeastern regions of China have contributed elevated PM 2.5 -bound PAHs from long-range transports.

This study was conducted during 2009–2010 to observe the concentration variations of metallic elements (Ni, Zn, Cu, and Pb) in the soil samples collected from five characteristic sites in central Taiwan (industrial, science park, urban, wetlands, and rural areas). The collected soil samples were first digested with hydrochloric and nitric acids, and then analyzed through inductively coupled plasma-atomic emission spectrometry (ICP-AES), using a Perkin Elmer Optima 2100 Plasma Emission Spectrometer. The results showed that the highest average concentrations of Zn, Cu, and Pb were found in the soil samples from the industrial area, suggesting that possible emissions of heavy metals from sources of metal industry and industrial processing. The wetland samples suggested possible emissions of heavy metal (Ni) from oil combustion sources. Heavy metal (Pb) was also found in the soils samples, possibly due to vehicle exhaust emissions.

The main purpose of this study was to monitor ambient air particles and particulate-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic-sampling sites. In addition, the calculated/measured dry deposition flux ratios of ambient air particles and particulate-bound mercury Hg(p) using three dry deposition models during the years of 2009–2010 were also studied. The results showed that the order of seasonal variations for mean particulate-bound mercury Hg(p) concentrations in TSP at Bei-shi (suburban/coastal), Chang-hua (downtown) and He-mei (residential) were all shown as spring > fall, winter > summer, respectively. However, the order of seasonal variations mean particulate-bound mercury Hg(p) concentrations in TSP that occurred at Gao-mei (wetland) were shown as spring > fall > winter > summer, respectively. Finally, the results of this study also indicated that using the Noll and Fang model exhibited batten prediction results for ambient air particles and particulate-bound mercury Hg(p) dry deposition when compared with the other depositions models at any of the characteristic-sampling sites for this study.

Ambient air samples were collected between September 3, 2009 and March 5, 2010 to determine total suspended particulate matter (TSP) and coarse and fine particulate and particle-bound mercury Hg(p) at the suburban/coastal sampling station of Sha-Lu at Taiwan. Results reveal that average concentrations of ambient air particles PM2.5, PM2.5–10, dry deposition, and TSP were 20.5 ± 6.3 (μg/m3), 11.2 ± 4.44 (μg/m3), 162 ± 92.7 (μg/[m2 min]), and 78.7 ± 34.4 (μg/m3), respectively. Average concentrations of PM2.5, PM2.5–10, dry deposition, and TSP of bound mercury Hg(p) were 0.007 ± 0.005 (ng/m3), 0.011 ± 0.006 (ng/m3), 0.156 ± 0.082 (ng/[m2 min]), and 0.07 ± 0.04 (ng/m3), respectively. Average calculated/measured dry deposition flux ratios with coarse (3.8 μm) and fine (0.68 μm) particle size for ambient air particle and particle-bound mercury Hg(p) by using Zhang's combined with William's were 2.49 and 3.44, respectively. Finally, results of this study also indicate that using Zhang's combined with Wi...

The main purpose for this study is to observe the seasonal and month variations for particulates-bound mercury Hg(p) in total suspended particulates (TSP) concentration, dry deposition at five characteristic sampling sites during years of 2009–2010 in central Taiwan. The results show that the highest and lowest monthly average particulates-bound mercury Hg(p) concentrations in TSP were occurred in Dec. and Oct. at Gao-mei (wetland), Chang-hua (downtown) and He-mei (residential) sampling site. In addition, the results show that the highest and lowest monthly average particulates-bound mercury Hg(p) dry deposition was occurred in Feb. and Oct. at Quan-xing (industrial) sampling site. This study reflected that the mean highest particulates-bound mercury Hg(p) concentrations in TSP and mean highest particulates-bound mercury Hg(p) dry deposition were occurred at Gao-mei (wetland) and Quan-xing (industrial). However, the mean lowest particulates-bound mercury Hg(p) concentrations in TSP and mean lowest particulates-bound mercury Hg(p) dry deposition were also occurred at Gao-mei (wetland). Regarding seasonal variation, the order of mean-particulates-bound mercury Hg(p) concentrations in TSP in winter and spring were Gao-mei (wetland) > Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential). Finally, the order of mean-particulates-bound mercury Hg(p) dry deposition in fall, spring and summer were Quan-xing (industrial) > Bei-shi (suburban/coastal) > Chang-hua (downtown) > He-mei (residential) > Gao-mei (wetland).

The paper reviewed studies about total gaseous mercury, atmospheric particulate of mercury and average dry deposition fluxes of mercury in Korea, Japan, China and Taiwan. This study compared sample collection and analytical methods for mercury in Asian countries. Analytical results indicated that the primary mercury sources are anthropogenic source (for example coal burning) and high temperature processes. This study also elucidates the sources, analytical tools, and the average concentrations for atmospheric mercury (Hg) for these Asian countries during 2000-2008. This study indicated that the total gaseous mercury concentrations were higher in urban area than that in suburban area in Asian countries (Korea, Japan, China and Taiwan). As for the seasonal variations, in general, the average total gaseous mercury concentrations were higher in winter than that in summer especially in China. In addition, the average total gaseous mercury concentrations were higher in mining areas than that in the rest of the other areas. And the total gaseous mercury concentrations were decreasing as this distance increasing. These phenomena revealed that the total gaseous mercury concentrations are reduced by long-distance transportation especially in the main land of China.

Ambient suspended particulates in an area abutting a highway were gathered using a Partisol Model 2300 Speciaton Sampler (RP2300). Major ionic species with different particle sizes and with possible sources close to the sampling site were evaluated using Principal Component Analysis (PCA). Observational results indicate that average PM2.5 and PM10 concentrations were 66.33 and 108.28 μg/m3, respectively. The average ratio of PM2.5/PM10 was 62% at this sampling site, whereas the average PM2.5/PM10 ratio in this study was less than those in urban (Seoul, Korea), suburban (Basel, Switzerland) and rural (Chaumont, Switzerland) settings. Average concentrations for ionic species of NO3−, SO42− and NH4+ were 10.46, 12.63 and 7.87 μg/m3 in PM2.5, respectively. Average concentrations for ionic species of NO3−, SO42− and NH4+ were 17.28, 15.59 and 9.48 μg/m3 in PM10, respectively. Principal component analysis identified soil, secondary aerosols and marine salt as possible major pollutant sources at this sampling site.

Ambient air particulate concentrations were sampled using an RP2300 Sampler (RP 2300, Rupprecht and Patashnick, CO, USA) from March 4 to April 2, 2006, at a sampling site near highway traffic. However particles that have an aerodynamic diameter of less than 10 μm (0.01 mm) are called respiratory particulates or particulate matter (PM10). PM2.5 denotes fine particles with an aerodynamic diameter of less than 2.5 μm (Ohlstrom et al., 2000). Analysis results indicated that the average mass concentrations of fine particles (PM2.5) and inhalable particles (PM10) were 64.43 and 109.20 μ g/m3, respectively, during the day. The average mass concentrations of PM2.5 and PM10 were 69.45 and 110.46 μ g/m3 during the night. Average concentrations of major ionic species, NO2 −, NO3 −, SO4 2 −, and NH4 + during the day were 2.37, 9.16, 13.72, and 7.70 μ g/m3 in PM2.5 and 3.72, 16.42, 16.90, and 8.91 μ g/m3 in PM10. The corresponding values at night were 3.29, 11.77, 11.55, and 8.03 μ g/m3 in PM2.5 and 3.87, 18.13, 14.27...

Numerous studies have monitored deposition velocity and dry deposition fluxes in Asia throughout the recent decade. This study compares different sample collections, pretreatments, and analytical methods utilized throughout the past decade in Asia. Analytical results suggest that the primary dry deposition sources are traffic and soil exhaust. This study also elucidates the sources, analytical tools, and the average concentrations in the Asian region for dry deposition and related metallic elements during 1997–2006. The order of metallic elements in average dry deposition fluxes in Asia was established as: Na > K > Mg > Fe > Ca > Zn > Pb > Mn > Cl > Cu > Cd > Cr, and in average atmospheric concentrations the order was observed as: Ca > Cl > Na > Fe > Mg > K > Zn > Cu > Pb > Mn > Cr > Cd. The order of metallic elements in average deposition velocity in Asia was Fe > Zn > Cd > Ca > Mn > Pb > Cr > Cu > Mg > Na > Cl > K.

The principal sources of organic carbon (OC) and elemental carbon (EC) are anthropogenic or biogenic, whereas secondary sources are atmospheric oxidation processes of specific precursor gases. These compounds are considered atmospheric contaminants and adversely affect human health. Numerous studies have monitored atmospheric particulates and gaseous phases of OC and EC in Asia over the last decade. This work compares and analyzes different sample collection, pretreatment and analytical approaches. The principal carbonaceous sources are traffic exhaust and industrial emissions. The OC and EC concentrations are highest in high traffic areas, followed by urban sites, and lowest in suburban sites. Many characteristics of these sites, such a dense population, are important to research. The major OC to EC ratios in Asia cities were 1.0-3.0. This work elucidates the characteristics, sources, distributions, and characteristics of atmospheric carbonaceous species in Asia.

The characterization of water-soluble species of dry deposition flux, total suspended particulates (TSPs), fine particles (particle matter with aerodynamic diameters 2.5 )), coarse particles (particle matter with aerodynamic diameter 2.5–10 μm (PM 2.5–10 )), and dry deposition velocity were studied at Taichung Airport sampling sites in central Taiwan between Sept. and Dec. 2004. The average TSP concentrations at Taichung Airport were about 0.8 times that of the harbor sampling site in central Taiwan. Additionally, the average dry deposition velocities (for TSPs) for metallic elements Fe, Mn, Cu, Zn, Pb, Cr and Mg were 1.54 ± 0.44, 0.86 ± 0.31, 0.77 ± 0.32, 0.62 ± 0.24, 1.21 ± 0.42, 0.82 ± 0.14 and 1.64 ± 0.26 (cm s − 1 ), respectively, at the airport sampling site. Furthermore, metallic element concentrations in fine and coarse particulate matter in air samples were also analyzed. The average ratios of fine to coarse for metallic elements Fe, Mn, Cu, Zn, Pb, Cr and Mg were 5.04 ± 1.87, 1.80 ± 0.60, 1.80 ± 0.76, 2.89 ± 0.72, 1.75 ± 0.36, 1.58 ± 0.39 and 2.33 ± 1.87, respectively. The results indicated that the metallic elements in the fine particulate matter accounted for the majority of particulates at the Taichung Airport sampling site.

The concentrations of total suspended particulate (TSP), fine particles (PM2.5) (with aerodynamic diameter < 2.5 μ m), coarse particles (PM2.5 − 10) (with aerodynamic diameter 2.5–10 μ m), and the related water-soluble ionic species (Cl−, NO2 −, NO3 −, SO4 2 −, Na+, NH4 +, K+, Mg2 +, and Ca2 +) were studied at the Taichung airport sampling site in central Taiwan during September to December 2005. The results showed that the TSP, PM2.5, and PM2.5 − 10 concentrations of particulate mass averaged 120.6, 38.1, and 24.2 μ g/m3, respectively. In general, the ionic species of SO4 2 −, NH4 +, and NO3 − were higher, being considered the major pollutants for traffic, suburban, rural, urban, and airport sampling sites in central Taiwan. Soil, secondary aerosol, and marine salt were the major pollutant sources at the Taichung harbor sampling site. In addition, the photochemical gas-phase oxidation is the predominant formation mechanism during summer at suburban and urban sampling sites. The secondary aerosol was the ...

Dividing measured fluxes by measured airborne concentrations for varying particle size range identified dry deposition velocities of various metals. This study attempts to identify the dry deposition flux and dry deposition velocity of metallic particulates among large inhalable particles (> 10 μ m [PM10]), coarse particles (10–2.5 μ m [PM2.5 − 10]), and fine particles (< 2.5 μ m [PM2.5) at the Taichung harbor (TH) and Taichung airport (TA) sampling sites in central Taiwan from September to December in 2004 and 2005, respectively. The results indicate that dust, vehicle emissions, and marine salts are the principal sources of coarse and fine particulates at the TH sampling site. The analytical results also suggest that the average concentrations of Fe, Mn, Cu, Zn, Cr, and Mg in the total suspended particulate fraction and in coarse particles are highest at the TH sampling site. Additionally, measurement data demonstrate that the average concentrations of Mn, Cu, Zn, Cr, and Mg are also high at the TH site...

This study monitored the atmospheric pollutants at the WuChi traffic (WT) sampling site from March 2004 to January 2005 near the Taiwan Strait in central Taiwan. The distributions of the particle concentrations between the total suspended particulates and the particulate matter around roads (fine particles and inhaled particles) at the WT sampling site were also determined. The variations in the concentrations of metallic elements (Fe, Mg, Cr, Cu, Zn, Mn, and Pb) and ions species (Cl−, NO3 −, SO4 2 −, NH4 +, Mg2+, Ca2+ and Na+) in those particles were also analyzed with reference to meteorological conditions. A nonparametric (Spearman) correlation analysis indicated that the meteorological conditions are closely correlated with the largest total suspended particulates at the WT sampling site. The results also indicated that the temperature importantly affected the particulate matter and was more closely correlated with particulate matter than other meteorological parameters such as wind speed, relative hu...

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter of total suspended particulate (TSP), fine particle (particle matter with aerodynamical diameter

The characterization for water-soluble species of total suspended particulate (TSP), dry deposition flux, and dry deposition velocity (V(d)) were studied at Taichung Harbor (TH) and Wuchi traffic sampling sites at offshore sampling site near Taiwan Strait of central Taiwan during March 2004-January 2005. The average concentrations of TSP and dry deposition flux at the TH sampling site were higher than at the WT sampling site during the sampling period. The samples collected were analyzed by a ion chromatography (DIONEX-100) for the ionic species (Cl(-), SO(4)(2-), NO(3)(-), NH(4)(+), Na(+), Ca(2+), and Mg(2+)) analysis. The dominant ionic species for TSP are SO(4)(2-), NO(3)(-), and NH(4)(+) of the total mass of the inorganic ions at both sampling sites. In addition, the results indicated that the NH(4)(+), NO(3)(-) and SO(4)(2-) showed higher concentrations in winter and lower in summer for both TH and Wuchi sampling sites. Statistical methods such as correlation coefficient and principal component analysis were also used to identify the possible pollutant source.

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.

Aerosol samples for dry deposition and total suspend particulates (TSP) were collected from August to November of 2003 in central Taiwan. Ion chromatography was used to analyze the related water-soluble ionic species (Cl(-), NO(3)(-), SO(4)(2-), Na(+), NH(4)(+), K(+), Mg(2+) and Ca(2+)). The results obtained in this study indicated that the ambient air particulate mass concentrations in the daytime period (averaged 975.4 microg m(-3)) were higher than the nighttime period (averaged 542.1 microg m(-3)). And the daytime dry deposition fluxes (averaged 58.12 microg m(-2) sec(-1)) were about 2.2 times as that of nighttime dry deposition fluxes (averaged 26.54 microg m(-2) sec(-1)) of the downward dry deposition. The average values downward and upward of dry deposition fluxes for the weekend period were almost higher than the weekday period for either daytime or nighttime period. Furthermore, the average daytime dry deposition fluxes (averaged 26.37 microg m(-2) sec(-1)) were also about 2.3 times as that of nighttime dry deposition fluxes (averaged 11.52 microg m(-2) sec(-1)). Moreover, the results also indicate that SO(4) (2-) and Ca(2+) have higher average composition for total suspended particulates in the daytime period while Ca(2+), SO(4) (2-), and Na(+) have the higher average composition for total suspends particulates in the nighttime period.

The purpose of this study is to characterize metallic elements associated with atmospheric particulate matter in dry deposition flux, total suspended particulate (TSP), fine particles (particle matter with aerodynamical diameter 2.5 ), coarse particles (particle matter with aerodynamical diameter 2.5–10 μm, PM 2.5–10 ), and dry deposition velocity, at the Taichung Harbor sampling sites in central Taiwan during February to December of 2004. Also the average dry deposition velocities (for TSP) for metallic elements Fe, Zn, Mn, Cu, Pb, Cr and Mg were 2.6, 1.0, 1.9, 0.2, 1.7, 0.6 and 1.4 (cm s − 1 ), respectively, at the harbor sampling site. In addition, metallic element concentrations and compositions in fine and coarse particulate for air sampling were also analyzed in this study. The average total suspended particulate concentrations with metallic elements Fe, Zn, Mn, Cu, Pb, Cr and Mg were 116.3, 119.4, 148.8, 139.9, 46.1, 24.4 and 88.5 ng m − 3 , respectively. The average ratios of coarse to fine for metallic elements Fe, Zn, Mn, Cu, Pb, Cr and Mg were about 1.9, 2.7, 3.8, 2.9, 1.6, 2.5 and 2.1, respectively. The results reflected that coarse particulate concentrations of metallic elements were the major species at the Taichung harbor sampling site. The results also identified dust, vehicle emissions and marine salt as the sources of fine particulates at Taichung Harbor near the Taiwan Strait. Most of the flux is due to particles larger than 2.5 μm in size due to their high deposition velocities. The result also indicates that the best approach to estimate overall dry deposition is by using either coarse particle or total particle concentrations.

The concentrations of ambient air polycyclic aromatic hydrocarbons were measured simultaneously from August 2002 to July 2003 in an industrial area (Taichung Industrial Park) and a suburban area (Tunghai University) in central Taiwan. Particle-bound PAH were collected on quartz filters and gas-phase PAH on glass cartridges using polyurethane foam sampler. Both types of samples used soxhlet analytical method and were subjected to gas chromatography-mass spectrometric analysis. Diagnostic ratios and principal component analysis were also used to characterize and identify PAH emission source in this study.

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.

The concentrations of gas-phase and particle-bound polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously at an industrial area (Taichung Industrial Park) and a suburban area (Tunghai University Campus) in Taichung, Taiwan. Twenty-four hours samplings for two consecutive days were performed between August and December 2002 at both sampling sites. Ambient air particle-bound PAHs were collected on quartz filters and gas-phase PAHs were collected on glass cartridges using a PUF Sampler, respectively. Both types of samples were extracted with a DCM/n-hexane mixture (50/50, v/v) for 24 h, then the extracts were subjected to gas chromatography–mass spectrometric (GC–MS) analysis. Total PAHs concentrations at the Taichung Industrial Park (TIP) sampling site and the Tunghai University Campus (THUC) sampling site were found to be 1232.3 ± 963.6 and 609.8 ± 356.3 ng/m3, respectively. Stationary combustion processes were mainly responsible for PAHs sources at the TIP sampling site, while traffic vehicle exhaust was the largest contributor for PAHs sources at the THUC sampling site.

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.

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.

Ambient suspended particulate concentrations were measured at Tzu Yun Yen temple in this study. This is characteristic place of incense burning and indoor air pollution sampling site. A universal sampler, micro-orifice uniform deposited impactor (MOUDI) sampler and dry deposition plate were used to measure particulate concentrations. Tzu Yun Yen temple is a typical famous Buddhist-Taoist combined temple, where many pilgrims come from different areas and various belief systems indicating the eclecticism of the temple. The average number of people visiting this temple is above 5000 per day. The PM2.5/PM10 ratios ranged between 31.2 and 87.4% and averaged 69.6+/-12.3% during the incense-burning period, respectively. The results also demonstrated that the fine particulates concentrations (PM2.5) constituted the majority of indoor-suspended particulates at Tzu Yun Yen temple. PM10 concentration was 110.1 microg m(-3) for Zhong Yuan Jie (A festival on the seventh full moon in a lunar year, otherwise known as a summer lantern festival and (or) the commemoration of the dead. Almost all temples have maximum pilgrims for the commemoration of the dead on this day.) and the 1st or 15th of nong li (Nong li is a Chinese lunar calendar system in which 1 year is divided into fixed periods, and the beginning and end of a year is determined. The new moon and full moon are the 1st and 15th, respectively of each month in the Chinese lunar calendar. Many pilgrims appeared at each temple for blessing and good luck for themselves on the 1st and 15th of each Chinese lunar month.) with numbers higher than non-Zhong Yuan Jie and non-1st or -15th day of nong li (average = 85.5 microg m(-3)). In general, the average dry deposition flux (49.4 mg m(-2) day(-1)) in the indoor environment is lower than those measured in the outdoor environment (184.0 mg m(-2) day(-1)) in this study. The mean dry deposition flux of indoor/outdoor ratio was 46.2%. The average mass size distributions were bimodal with the major peaks within 0.56-1 microm and 5.6-10 microm, respectively during non-Zhong Yuan Jie and non-1st or -15th days of each month (Chinese lunar calendar). The average mass size distributions were bimodal with the major peaks within 0.18-0.32 microm and 5.6-10 microm, respectively during Zhong Yuan Jie and the 1st or 15th of nong li of each month (Chinese lunar calendar) at Tzu Yun Yen temple.

This experiment was conducted during November in 2000 and February in 2001 in Taichung, central Taiwan. The study used a TE-PUF sampler, Universal air sampler and MOUDI (Micro-Orifice Uniform Deposit Impactor) sampler to collect the ambient air suspended particles and analyzed their water-soluble ions (Cl-, NO3-, SO42-, Na+, NH4+, K+, Mg2+ and Ca2+). Analytical results indicate that the mean mass concentration for PM2.5, PM2.5-10 and TSP measured at the CCRT (traffic) sampling site are 54.5, 27.8 and 158 μm/m3, respectively. Additionally, the mean mass concentration for PM2.5, PM2.5-10 and TSP measured at the THUC sampling site are 23.6, 16.3 and 85.6 μm/m3, respectively. Furthermore, the major water-soluble ion of PM2.5 measured in this sampling region are SO42- and NH4+, while those of PM2.5-10 are Cl-, NO3- and SO42-, respectively. At the CCRT (traffic) sampling site, the mean size distributions of mass, SO42- and NH4+ exhibit a bimodal distribution whereas those of Cl-, NO3-, Na+, K+, Mg2+ and Ca2+ have a bimodal distribution. At the THUC (campus) sampling site, the mean size distributions of mass, Cl-, NO3-, SO42- and Ca2+ are bimodal whereas those of Na+, NH4+, K+ and Mg2+ have display a unimodal distribution.

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, PM2.5–10 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, PM2.5–10 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.

Fine and coarse particles were collected by Universal sampler from June 1999 to January 2000 in Sha‐Lu, Taiwan. Concentrations of the inorganic chemical species (NO2 ‐, NO3 ‐, SO4 2‐, NH4 +, Cl‐, Mg2+, Ca2+, K+, Na+) in particulate phase were analyzed by ion chromatography. Two sampling sites were set inside and outside the campus of Hung‐Kuang Institute of Technology, and measurements in two sampling sites were carried out simultaneously from September 1999 to January 2000. The sampling site outside school was located on an overbridge above Chung‐Chi Road, named as CCROB. The sampling site inside campus was located on the roof of an eight‐story building, named as HKJ.T. Results showed that average coarse particle concentrations measured at HKIT were 1.16 times as that measured at CCROB. For the chemical composition of fine and coarse particles, sulfate and ammonium were distributed in fine particles. Nitrite, nitrate and chloride were distributed in coarse particles. The major salts existed in f...

During June 1999 to January 2000, the concentrations of acidic gas were measured by ADS (annular denuder system) in central Taiwan, Taichung. The concentration of HNO2, HNO3, SO2, NH3and HCl were 2.81, 1.63, 24.69, 15.75 and 1.08 μg/m3, respectively. For the seasonal variations of acidic gases, the average SO2and NH3concentrations were higher in summer, and lower in winter. Contrarily, the HNO2and HNO3concentration were lower in summer, and higher in winter. Four meteorological factors: wind speed (m/s), wind direction, temperature (°C) and relative humidity (%) were taken into account in this study. Concentrations (μg/m3) of SO2and NH3were moderate positive related to temperature (°C) with R2 value of 0.668 and 0.678, respectively. The highest value of average SO2gas concentrations appeared in the SSW direction. It meant that the Taichung thermal power station which located in the west side of the sampling site were not the largest SO2contributor to the sampling area. The factories surrounded in...

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 size2.5 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.

Daily PM2.5, PM2.5–10 and TSP have been collected by Universal and PS‐1 sampler simultaneously at a site within Taichung between February and March 1999. The filters were analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Mn, Pb, Cu, Zn and Cr. In general, the concentration of these metallic elements are higher in fine particles than in coarse particles. On average, PM10 accounted for 67% of the TSP at daytime, while at nighttime PM10 accounted for only 44% of the TSP. For PM2.5, PM2.5–10 and TSP concentrations, there were no significant differences between day and night period. The averaged concentrations of metallic elements in PM2.5 at daytime were all higher than that at nighttime. Ca, Fe and Zn have large and variable PM2.5 concentrations at both daytime and nighttime. For the daytime Zn and Pb account for the largest portion of the heavy metal elements. For the nighttime, Zn and Cr make the largest portion of the heavy metal elements. The concentrations of Mn were ...

Aerosol samples of particulate and chemical species for PM10 (particulate matter with aerodynamic diameters less than 10 μm) collected by Universal sampler were studied from June to August 1998 in the suburban area of central Taiwan. The ratios of PM2.5/PM2.5–10 displayed that the fine particles (particle size < 2.5 μm) are prevailing in the suburban site. Ion Chromatography was used to analyze for the water‐soluble ions: sulphate and nitrate in the Universal samples. Also, the collected samples were analyzed by atomic absorption spectrophotometry for the elemental analysis of Ca, Fe, Pb, Cu and Cr. The results indicated that the crustal elements (Ca and Fe) and resuspended matters were dominated in the coarse particulate mode while the anthropogenic elements (Cr, Pb, Cu) and sulphate components are mainly in the fine particle fraction. The results also showed that the sulphate and nitrate make the largest portion of the chemical species collected by Universal sampler (PMio). The concentrations of heavy m...

The main purpose of this investigation was to monitor ambient air particles and metallic elements (Cr, Cu and Pb) in total suspended particulates (TSP) concentration, dry deposition. Furthermore, the calculated/measured dry deposition flux ratios of ambient air particles and metallic elements (Cr, Cu and Pb) were evaluated using three dry deposition models at five characteristic sampling sites for the 2009-2010. The results show that the average concentrations of metallic elements Cr, Cu and Pb in TSP were highest at Bei-shi (suburban/coastal) and the lowest at Gao-mei (wetland) among the five characteristic sampling sites during the years 2009-2010. This study also shows that the mean rates of dry deposition of metallic elements Cr and Cu were highest at Quan-xing (industrial) and lowest at Bei-shi (suburban/coastal) and Chang-hua (downtown). Finally, the Noll and Fang model was found to yield better predictions of the dry deposition of ambient air particles and metallic elements Cr and Cu than any of the other deposition models.

For reasonable and convenient assessments of the characteristics of the dry deposition velocities between Taichung harbor site and Wuchi town site in central Taiwan, the overall dry deposition velocities of several metallic elements were calculated as the particulate diameter (D(p)) distributions of large particles (D(p)10 microm), coarse particles (10 micromD(p)2.5 microm), and fine particles (D(p)2.5 microm) based on the ambient measurements during March-December of 2004. In this work, the dry deposition fluxes showed the higher correlation with coarse particle concentrations than large particle concentrations; however, the least well correlation was observed between the dry deposition fluxes and the fine particle concentrations. The calculated best-fit overall dry deposition velocities obtained using coarse particle concentrations varied from approximately 0.2 cm s(-1) for Cr to 1.5 cm s(-1) for Pb and 0.2 cm s(-1) for Fe to 2.6 cm s(-1) for Pb at Taichung harbor and Wuchi town site, respectively. In general, the crustal elements had higher deposition velocities than anthropogenic elements. In addition, overall dry deposition velocities for crustal elements were higher in Wuchi town site than in Taichung harbor site. The results identified the dry deposition flux was mainly contributed from large and coarse particles due to their high deposition velocities. The results also indicated that the best approach to estimate overall dry deposition was by depending on the characteristics of particles with diameters larger than 2.5 microm.

In addition to determining the concentration and metallic constituents of particulate matter at Taichung Harbor in central Taiwan, this study attempts to characterize the mass, metallic elements, composition and concentrations of total suspended particulates (TSP), fine particles and coarse particles. Statistical approaches, such as the Spearman tests, were also adopted to determine the seasonal variations of concentrations of these pollutants. Experimental results indicate that the mean TSP, fine particulate and coarse particulate concentrations in spring and winter are higher than in summer and autumn on the western coast of central Taiwan. Spearman statistical analysis of metallic elements Mn and Pb showed high concentration coefficients for fine and coarse particulates on the western coast of central Taiwan. The order of mean metallic concentrations in TSP, coarse particulates and fine particles was Fe>Zn>Mg>Cu>Cr>Mn>Pb in TSP, Fe>Cu>Zn>Mg> Mn>Pb>Cr in coarse particulates and Fe>Cu>Mg>Pb>Zn>Mn>Cr in fine particulates. Toxicology and Industrial Health 2006; 22: 193-201.

Many studies have monitored atmospheric particulates and gaseous phases of PM 2.5 in Asia over the past 10 years. This work also compared and discussed different sample collection, pretreatment and analytical methods in Asia countries in past decade. The results indicated that the main PM 2.5 sources are traffic exhausts. PM 2.5 concentrations are also ranked highest in the areas of traffic, followed by the urban sites, and lowest in rural sites in Asian countries. This work elucidates the sources, analytical tools, and the average concentrations for PM 2.5 and related metallic elements during 1995–2005. The results indicated that the average highest concentrations order of metallic elements for PM 2.5 were Fe > Mg > Zn, and the average concentrations of lowest metallic elements was Pb > Cu > Mn > Cr > Cd. The results also indicated that the concentration of metallic element Cu increased as the averaged concentrations of metallic element Zn and Mn increased during the past 10 years in Asian countries.

This study monitored the atmospheric pollutants at Taichung airport (TA) sampling site during September to December of 2005 near Taiwan Strait in central Taiwan. The distributions of the particle concentrations between the TSP, coarse and fine were also displayed at TA sampling site. Analysis the average percentage of various kinds of metallic elements, the data obtained here indicated that the average percentage concentrations of metallic elements Fe and Mg were higher in fine particulate than that of the coarse particulate at Taichung airport sampling site. These foundry factories were by the TA sampling site was the possible reason responsible for this result. In addition, by a non-parametric (Spearman) correlation analysis, the results indicated that Fe, Mn and Pb have high correlation coefficients of metallic elements in different particle size. The results indicate that the airport pollutants might come from similar pollutant sources at this airport sampling site. In addition, high correlation coefficients of non-airport pollutants were observed on the ionic species of SO(4)(2-), NH(4)(+) and K(+). The r(sp) correlate values between closed to r(sp)=0.7 and 0.9 at different particles size mode. Besides, the ionic Ca(2+) has high negative values (r(sp)=-0.66, -0.66 and 0.61) with the increasing of the temperature, relative humidity and wind speed, respectively at fine particle size.

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 (SO42- and NO-3) in other Asian regions.

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, SO42, 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.

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

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.

Polycyclic aromatic hydrocarbons (PAHs) are present in both gaseous and particulate phases. These compounds are considered to be atmospheric contaminants and are human carcinogens. Many studies have monitored atmospheric particulate and gaseous phases of PAH in Asia over the past 5 years. This work compares and discusses different sample collection, pretreatment and analytical methods. The main PAH sources are traffic exhausts (AcPy, FL, Flu, PA, Pyr, CHR, BeP) and industrial emissions (BaP, BaA, PER, BeP, COR, CYC). PAH concentrations are highest in areas of traffic, followed by the urban sites, and lowest in rural sites. Meteorological conditions, such as temperature, wind speed and humidity, strongly affect PAH concentrations at all sampling sites. This work elucidates the characteristics, sources and distribution, and the healthy impacts of atmospheric PAH species in Asia.

Fine (PM 2.5 ) 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 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 PM 2.5 (fine particulate) and PM 2.5–10 (coarse particulate) total PAHs concentrations at the Tunghai University Pastureland sampling site were found to be 180.62 ng m −3 and 164.98 ng m −3 , respectively. In general, the concentrations of polycyclic aromatic hydrocarbons were higher in spring and winter than those of summer and autumn for either PM 2.5 or PM 2.5–10 in Pastureland in central Taiwan. Moreover, coarse particulates are the dominant species during the dust storm season (March and April) in central Taiwan.

Downward, upward dry deposition fluxes and total suspended particulate of particulate heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) were measured in daytime and nighttime period in Sha-Lu, a small city in the central Taiwan during summer period of 2003. The results showed that the total suspended particulate concentrations of particulate mass in the daytime period (averaged 996.2 g/m3) were higher than in nighttime period (averaged 560.7 g/m3). And the downward dry deposition fluxes (averaged 54.07 g/m2 s) were about two times as that of upward dry deposition fluxes (averaged 26.48 g/m2 s) in the daytime period. Furthermore, the average downward dry deposition fluxes (averaged 26.22 g/m2 s) were also about two times as that of upward dry deposition fluxes (averaged 12.11 g/m2 s) in the nighttime period. In addition, the average downward dry deposition fluxes are greater than the upward dry deposition fluxes for all the heavy metals in either daytime or nighttime period. The proposed reasons are that the wind speed and concentration difference for daytime and nighttime period lead to these results at the traffic sampling site of central Taiwan. In addition, the deposition velocity for mass, heavy metals (Fe, Pb, Zn, Cu, Mg and Mn) during daytime and nighttime period were also calculated. The average daytime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 5.56, 2.66, 1.71, 0.18, 1.06, 0.24, 0.47 and 0.11 (cm/s), respectively. And the average nighttime dry deposition velocity for downward particulate mass, upward particulate mass, Fe, Pb, Zn, Cu, Mg and Mn were 4.70, 2.11, 1.66, 0.18, 0.86, 0.23, 0.32 and 0.07 (cm/s), respectively at traffic sampling site of central Taiwan.

Suspended particulate concentrations were measured at the Tzu Yun Yen temple in the Taichung region of Taiwan. The temple performs traditional incense burning. A universal sampler and a micro-orifice uniform deposited impactor (MOUDI) sampler with a dry deposition plate were used to measure the particulate concentrations. The results show that the average PM2.5/PM10 ratio was 74% during the incense burning period at this temple. In addition, the average suspended particulate (PM10) element concentration of anthropogenic element Zn (495 ng/m3) was higher than the other anthropogenic elements (Pb, Mn, Ni, and Cd). Furthermore, the average mass size distribution was bimodal with major peaks occurring at 0.32-0.56 mm and 5.6-10 mm during the incense burning period. The dry deposition velocities of Cd used fine particulates (PM2.5) and suspended particulate (PM10) mode were 1.86 and 0.99 cm/s in this study, respectively.