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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.

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 PM

This review focuses on the concentrations of ionic species (Cl−, NO− 3, SO2− 4, Na+, NH+ 4, K+, Mg2+, and Ca2+) in ambient air in Asian countries during the years 1995–2009. The main likely source of the ionic species Cl−was the ocean while the source of NO− 3and SO2− 4was fossil fuel power stations, and that of Ca2+was terrestrial dust and alkaline particles from cement factory plants. The highest average concentrations of the ionic species Na+and Mg2+in total suspended particulates (TSP) were found in Hong Kong. The highest average concentrations of ionic species Na+, K+, and Ca2+in PM2.5 were found in Nanjing, China, while those of NO− 3and SO2− 4were found in Sha-Lu, Taiwan. The highest average concentrations of Cl−and NH+ 4were found in Beijing, China, while that of Mg2+was found in Shanghai, China.

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.

This study investigates PM

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 main purpose of this study is to observe the seasonal variations of total suspended particulates (TSP) concentration, dry deposition (and the metallic elements that attach to them) at five characteristic sampling sites in Taiwan during the years of 2009 and 2010. The highest average concentration in TSP for metallic elements Mn and Fe occurred in Quan-xing (industrial area), while the highest average concentration in TSP for metallic elements Cr, Cu, and Pb was observed in Bei-shi (suburban/coastal area). The lowest average concentrations for metallic elements in TSP occurred in Gao-mei (wetland area). In addition, the highest average dry deposition for metallic elements Mn, Fe, and Zn was observed in He-mei (residential area). Also, the highest average dry deposition for metallic elements Cr, Cu, and Pb occurred in Quan-xing (industrial area). The lowest average dry deposition for metallic elements Mn, Fe, and Cr occurred in Bei-shi (suburban/coastal), while the lowest average dry deposition for meta...

The possibility of using Bidens pilosa L. var. radiate Sch leaves as environmental indicators of metallic element pollution has been investigated. Samples were analyzed with respect to the following pollutants: Zn, Mn, Cu, Ni, Pb, Cd, Cr, Fe, Ca, and Mg by using inductively coupled plasma atomic emission spectrometry. The results obtained on the metallic elements had the following average composition order: Ca > Mg > Fe, Mn > Zn > Cu > Ni > Pb > Cr > Cd for plant B. pilosa L. var. radiate Sch. at HK sampling site. In addition, the metallic elements had the following average composition order: Ca > Mg > Fe > Mn, Zn > Cu > Ni > Pb > Cr > Cd for plant B. pilosa L. var. radiate Sch. at TMP sampling site. Finally, the metallic elements had the following average composition order: Ca > Mg > Fe > Zn > Mn > Cu > Pb > Ni > Cr > Cd for plant B. pilosa L. var. radiate Sch. at LH sampling site. The seasonal average composition for metallic elements Mg, Fe, and Pb were ranked highest at HK sampling site in winter. In addition, seasonal average composition for metallic elements Mn, Zn, and Cd were ranked highest at TMP sampling site in winter. Finally, seasonal average composition for metallic elements Mg, Fe, and Cu were ranked highest at LH sampling site in spring.

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...

This work attempts to characterize metallic elements associated with atmospheric particulate matter on a dry deposition plate, a TE-PUF high-volume air sampler and a universal air sampler. Dry deposition fluxes of particulates and concentrations of total suspended particulate, fine (PM 2.5 ) and coarse (PM 2.5–10 ) particulate matters were collected at Taichung harbor sampling sites from August 2004 to January 2005. Chemical analyses of metallic elements were made using a flame atomic absorption spectrophotometer coupled with hollow cathode lamps. Concentrations of metal elements in the forms of coarse particles and fine particles as well as the coarse/fine particulate ratios were presented. Statistical methods such as correlation analysis, principal component analysis and enrichment factor analysis were performed to compare the chemical components and identify possible emission sources at the sampling sites. Metallic elements of Cu, Zn, Pb, Cr, Ni and Mg had higher EF crust ratios in winter and spring than in summer and autumn. Diurnal and nocturnal variations of metallic element concentrations in fine and coarse particles were also discussed.

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.

In November 2004–January 2005, a micro orifice uniform deposit impactor (MOUDI) and a Nanometer (nanometer)-MOUDI were used in the center of Taiwan to measure particle size (18 nm ≦ particle size ≦ 18 μm) distributions of atmospheric aerosols at a traffic site during the winter period. The average Mass in Media Aerodynamic Diameter (MMAD) of suspended particles is 0.99 μm this study. As for the ultra fine and nanometer (nanometer) particle mode, the composition order for these major ions species was SO 4 2− ≦ NH 4 + ≦ NO 3 − ≦ Mg 2+ ≦ Ca 2+ ≦ Na + ≦ K + ≦ Cl − . An ion Chromatography (DIONEX-100) was used to analyze major anion species, Cl − , NO 3 − , SO 4 2− and cation species, NH 4 + Na + , K + , Ca 2+ Mg 2+ . Their concentrations were also extracted from various particles size modes (nanometer (nanometer), ultra fine, fine and coarse). The results obtained in this study also indicated that the average portions for the major ionic species (SO 4 2− , NH 4 + and Mg 2+ ) in the nanometer (nanometer), ultra fine, fine and coarse particulate modes are about 34%, 37%, 63% and 30%, respectively at this traffic sampling site during the winter 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.

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.

Daytime and nighttime period sampling programs were carried out by a versatile air pollutant system (VAPS) to collect the fine (PM2.5) and coarse (PM2.5–10) particulates simultaneously at a traffic sampling site in front of Hungkuang University during August to October 2003. Chemical analyses of metallic elements were accomplished by a flame atomic absorption spectrophotometer coupled with hollow cathode lamps. Statistical methods, such as correlation coefficients and principal component analysis (PCA), were used to compare chemical components and to find the possible emission sources at this traffic sampling site. The variations of metallic element concentrations in fine and coarse particulates during daytime and nighttime were also discussed in this study.

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.

Aerosol samples for total suspended particulate matter were collected by two PS-1 samplers from October 2002 to April 2003 at Tunghai University and Taichung Industrial Park in central Taiwan. The average concentrations of TSP at the industrial sampling site were higher than at the suburban sampling site during the sampling period. The samples collected were analyzed by a flame atomic absorption spectrophotometer for the elemental analysis. Statistical methods such as correlation coefficient and principal component analysis were also used to identify the possible pollutant source.

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.

Stereoselective metabolism of dibenzo[a,l]pyrene (DB[a,l]P), 2-chlorodibenzo[a,l]pyrene (2-Cl-DB[a,l]P) and 10-chlorodibenzo[a,l]pyrene (10-Cl-DB[a,l]P) by rat liver microsomes was studied and effects of the chloro substituent on the metabolism were determined. All three compounds produced trans-8,9-dihydrodiol, trans-11,12-dihydrodiol, and the 7-hydroxyl derivative as major metabolic products and several other phenolic derivatives as minor metabolites. The trans-8,9- and 11,12-dihydrodiols of DB[a,l]P and 2-Cl-DB[a,l]P preferentially adopted a quasidiequatorial conformation, whereas 10-Cl-DB[a,l]P trans-8,9- and 11,12-dihydrodiols preferentially adopted a quasidiaxial conformation. The yields of the trans-11,12-dihydrodiol metabolites are: DB[a,l]P trans-11,12-dihydrodiol > 2-Cl-DB[a,l]P trans-11,12-dihydrodiol >> 10-Cl-DB[a,l]P trans-11,12-dihydrodiol. Circular dichroism (CD) spectral analysis indicates that the trans-8,9-dihydrodiol and trans-11,12-dihydrodiol metabolites from DB[a,l]P, 2-Cl-DB[a,l]P, and 10-Cl-DB[a,l]P are optically active. Furthermore, the major enantiomeric DB[a,l]P trans-11,12-dihydrodiol and 2-Cl-DB[a,l]P trans-11,12-dihydrodiol had R,R absolute configuration. Based on the fact that DB[a,l]P trans-11,12-dihydrodiol is the proximate tumorigenic metabolite of DB[a,l]P, our results suggest that DB[a,l]P exhibits the highest tumorigenic potency followed by 2-Cl-DB[a,l]P, and 10-Cl-DB[a,l]P exhibits the lowest tumorigenicity.

Background : A method for determining extracellular magnesium (Mg) levels in gerbil brain dialysates was developed by microdialysis and graphite furnace atomic absorption spectroscopy (GFAAS). Methods : Two microdialysis probes were inserted into the right and left cortices of a gerbil subjected to a focal cerebral ischemia. Extracellular magnesium concentrations in diluted dialysates were 1.10 and 1.12 ppb in the ipsilateral and contralateral gerbil cortex, respectively. Results : During cerebral ischemia, these concentrations decreased significantly to approximately 60% of basal in the ipsilateral cortex, whereas no changes in the contralateral cortex were detected. Extracellular magnesium concentrations returned to baseline within 3 h of reperfusion. The linearity of magnesium concentrations ranged from 0.50 to 5.0 ppb with a detection limit of 0.03 ppb in the present assay. A complete analysis can be performed within 2 min. The intra- and interassay precision was Conclusion : To our knowledge, the present method is the first analytical assay measuring dynamic extracellular magnesium concentrations during cerebral ischemia by microdialysis and graphite furnace atomic absorption spectroscopy.

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.

A microdialysis sampling device was constructed for the measurement of pyruvate and lactate in primary liver cell culture medium during hypoxia. It was composed of a Petri dish, a dialysis membrane and two transmission tubes within a hypoxia chamber. The dialysis membrane was located in the Petri dish such that it was immersed in the culture medium. Dialysates were collected and introduced by an on-line injector to a liquid chromatographic system for analysis of pyruvate and lactate. The detection limit of this assay was 0.2-2.0 microM with acceptable intra- and inter-assay reproducibilities. In order to validate the assay, primary liver cells were incubated in the Petri dish within a hypoxia chamber in an incubator. The baseline concentrations of pyruvate and lactate in primary liver cell culture medium were 10.6+/-5.6 and 607+/-143 microM, respectively. These levels drastically changed during hypoxia and reperfusion. In conclusion, the present assay provides a sensitive, direct measurement of pyruvate and lactate in culture medium while minimizing pretreatment procedures for sample preparation.

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 ...