Sampling Site In Central Taiwan Research Articles

Particle size distributions and seasonal concentrations study of atmospheric pollutants (particulates, Hg(p)) at an agricultural site in Taiwan

The concentrations of ambient air particulates of various sizes (PM1, PM2.5, PM6.25, PM10 and PM18) were measured using a MOUDI sampler at an agricultural sampling site in central Taiwan from January to September, 2020. The concentrations of particulate-bound mercury Hg(p) that were attached to particulates of various sizes (PM1, PM2.5, PM6.25, PM10 and PM18)) were analyzed using a Direct Mercury Analyzer (DMA-80). The results revealed that the mean particulate and Hg(p) concentrations associated with PM18, PM10, PM6.25, PM2.5 and the back filter were all highest in autumn and winter. The mean mass median diameter (m.m.d.) value for ambient air particulates was highest in the summer and lowest for Hg(p). The mean m.m.d. value for ambient air Hg(p) was highest in the winter and lowest for ambient air particulates. The northeast monsoon prevails in the winter season of Taiwan. Thus, The sources of particulates and Hg(p) pollutants might came from the northeast side of Taiwan - especially in spring and winter seasons. Thus, ambient air particulate concentrations are higher in the winter than in the spring. However, ambient air particulate-bound mercury Hg(p) tended to be associated more with coarse particulates than with other particulates. Finally, Hg(p) concentrations in Taiwan have increased over the last 15 years. Reducing atmospheric Hg(p) concentrations has become an important environmental goal in all countries - especially those in Asia.

A study of atmospheric pollutants (particulates, metallic elements) at an agricultural site

In this study, the total suspended particulate (TSP) concentrations and dry deposition of ambient air particulates are measured using a high-volume air sampler and a dry deposition plate at an agricultural sampling site in central Taiwan from March of 2019 to February of 2020. In addition, the concentrations of metallic elements attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). Finally, the TSP and metallic elements concentrations in TSP at different sampling sites around the world are also compared and discussed. The results indicated that the average highest TSP concentrations and dry depositions values both occurred in autumn, and the agricultural sampling site had the average greatest ambient air particulates dry depositions velocities when compared with other previous characteristic-related studies in Taiwan. In addition, metallic element Al had the average highest concentrations and dry depositions and metallic element Cd had the average lowest concentrations and dry depositions values in this study. In addition, metallic elements Cr, Cu, Pb, and Zn had the average highest concentrations when compared with other typical sampling site studies (airport, suburban, downtown, residential, industrial, and wetlands) in central Taiwan. Furthermore, when compared with the other previous metallic elements concentrations found in related studies in other regions from 1978 to 2020, the results obtained in this study indicated that the average metallic element concentrations Cr, Cu, Pb, and Zn in Taiwan were only lower than those reported in India and China. Taiping District is the main fruits production area in central Taiwan. Therefore, continued monitoring of ambient air related pollutants and finding the possible pollution sources have become an important issue for this agricultural site. From the above analysis, we also conclude that ambient air particulates and all the metallic elements dry deposition values obtained in this study were higher than those from the other characteristic sampling sites where studies were previously conducted in Taiwan.

Particulates and metallic elements pollutants concentrations, dry depositions and sources study at a suburban area

In this study, the concentrations and dry deposition of ambient air particulates are measured using a PS-1 sampler and a dry deposition plate at a suburban sampling site in central Taiwan from January 2019 to August 2019. The concentrations of metallic elements that are attached to the particulates and dry deposits are analyzed using inductively coupled plasma atomic emission spectroscopy (ICP-AES). The source analysis model was used to identify possible emission sources of the pollutants and the transmission distributions of ambient air metallic elements. During the sampling period, the TSP concentration at the Peiying suburban sampling site was highest on January 24th (in winter) and lowest on April 29th (in spring). Dry deposition was greatest on January 9th (in winter) and least on July 29th (in summer). In addition, the correlation coefficient between temperature and ambient air particulate concentration revealed a moderate to strong negative relationship (r2 = 0.60) the ambient air particulate concentrations declined throughout the study period. Moreover, high concentrations of crustal metallic elements Al, Ca were found in this study due to the particulates suspensions from the roads in the suburban area. The Taiwan II express highway runs about 500 m to the northeast of the sampling site, explaining why high concentrations of Cu were measured in this study. The concentrations of metallic elements Ca, Cd, Ni, Pb, and Zn were highest in winter and spring while those of metallic elements Al, Cu, Cr, and Mn were highest in summer. The mean metallic elemental concentrations followed the order: Ca > Al > Zn > Cu > Mn > Ni > Pb > Cr > Cd. The dry depositions of metallic elements Ca, Pb, Zn, Ni and Cd were greatest in winter and spring and those of metallic elements Al, Cu, Cr and Mn were highest in summer. The average dry depositions of the studied metallic elements followed the order: Ca > Al > Zn > Cu > Mn > Ni > Pb > Cr > Cd. The main pollution parcel was from the north side of Taiwan, pollution parcel that associated with the northeast monsoon, resulted in ambient air pollutants emitted on Taiwan island, influencing its air quality.

Dry, wet depositions for ambient air nitrate, sulfate, and chloride ionic species at mixed (traffic, commercial, and residential) sampling sites in Central Taiwan

This research was focused on the measurements of ambient air pollutants species (Cl−, NO3−, and SO42−) concentrations of wet and dry depositions by using PS-1 (TSP), dry depositions plate and wet depositions tub at mixed (traffic, commercial, and residential) sampling sites. Lu-Liao, characterized by traffic, commercial and residential sites, was selected as the dry deposition measurement site. Hungkuang University, characterized by a traffic site, was selected as the wet deposition collection site. At the Luliao site, the results indicated that the average ionic species (Cl−, NO3−, and SO42−) concentrations were 12.86, 25.58, and 18.37 μg/m3, respectively, in winter and 2.94, 11.37, and 14.09 μg/m3, respectively in spring. The average ionic species (Cl−, NO3−, and SO42−) dry depositions were 284.43, 1808.50, and 412.93 μg/m2 min, respectively, in winter and 147.66, 109.59, and 415.44 μg/m2 min, respectively, in spring. As for the monthly Cl−, NO3−, and SO42− volume weighted mean (VWM) concentrations at the Hungkuang site, the results for January were 5.64, 4.41, and 10.13 mg/L, for May were 0.45, 1.98, and 2.09 mg/L, for June were 0.76, 1.39, and 2.46 mg/L, and for July were 1.83, 2.97, and 5.84 mg/L. The monthly Cl−, NO3−, and SO42− Fw (Fluxwet deposition) at the same site were 355.41, 277.63, and 638.15 mg/m2 month, respectively, for January; 17.01, 99.03, and 362.05 mg/m2 month, respectively, for May; 99.03, 181.18, and 319.45 mg/m2 month, respectively, for June; and 362.05, 587.86, and 1156.49 mg/m2 month, respectively, for July. SO42− had the highest VWM and Fw values when compared with the other ionic species, Cl− and NO3−. The highest VWM values for all ionic species (Cl−, NO3−, and SO42−) all occurred in winter.

Measurement of ambient air particulate pollutant concentrations and dry depositions for PS-1 combined with dry deposition plate at a wetland site

In this study, the concentrations of ambient total suspended particulates (TSP) and their dry deposition were measured using a PS-1 sampler with dry deposition plates at a wetland sampling site in central Taiwan during a sampling period from October 2016 to December 2016. The PS-1 sampler was fixed at set distances (1.5 and 2 m) from a dry deposition plate, and sampled particulate pollutants were sampled to determine their concentrations and dry deposition rates simultaneously. A dry deposition plate 3 m from the PS-1 sampler was also used to collect dry deposition particulate. This plate was also used to compare dry depositions from ambient air, collected from new device. The results thus obtained indicated that the average dry deposition rates on the dry deposition plates that were 1.5 and 2 m from the sampler were 103.15 and 103.94 µg/m2 min, respectively, in October, 83.36 and 100.18 µg/m2 min in November, and 171.2 and 157.5 µg/m2 min in December. These dry deposition rates were compared with that 3 m away from the PS-1 sampler. The statistical t test revealed no significant differences between the dry depositions on dry deposition plates at 1.5 and 2 m from the sampler. The dry deposition rates at 1.5 and 2 m from the sampler did not differ significantly from that at 3 m from the PS-1 sampler. This study proves that a PS-1 sampler can be combined with a dry deposition plate to measure TSP concentrations and dry depositions simultaneously using a single device.

Flux of fine and coarse particulates and metallic pollutants at a commercial site

ABSTRACTThe concentrations of TSP, PM2.5, PM2.5–10, and metallic elements that are attached to PM particles (Al, Cr, Mn, and Pb) in ambient air were obtained using a PS-1 sampler and a MOUDI sampler from December 2015 to May 2016 at a commercial sampling site in central Taiwan. The mean concentration of coarse particulates and of metallic elements (Al, Cr, Mn, and Pb) attached to them were 28.42 µg/m3 and 472.05, 57.84, 33.66, and 161.08 ng/m3, respectively. The mean concentrations of fine particulates and metallic elements (Al, Cr, Mn, and Pb) that were attached to them were 69.73 µg/m3 and 399.06, 71.27, 39.25, and 220.70 ng/m3, respectively. Finally, the mean concentrations of TSP particulates and metallic elements (Al, Cr, Mn, and Pb) that were attached to them were 91.12 µg/m3 and 548.76, 16.07, 33.30, and 40.58 ng/m3, respectively. The results from this study show that the calculated coarse particulate fluxes for particulates and metallic elements (Al, Cr, Mn, and Pb) attached to them exceeded the calculated fine particulate fluxes. The mean calculated coarse particulate (PM2.5–10)/calculated fine particulate (PM2.5) flux ratio was approximately 6.76, and the corresponding ratios for the metallic elements Al, Cr, Mn, and Pb attached to the particulates were 4.94, 2.83, 2.96, and 2.17, respectively.

Ambient air particle and metallic pollutant dry deposition study at a farmland sampling site during 2013–2014

ABSTRACTIn this study, the concentrations of particulate and metallic pollutants (Cu, Cd, Cr, Pb, and Zn) in ambient air and dry deposits were monitored in daytime sampling periods at a farmland sampling site in central Taiwan from August 2013 to July 2014. Ambient air dry deposition models of dry deposition from ambient air (Noll et al., 2010) were used to determine the differences between measured and modeled concentrations of pollutants in ambient air and dry deposits. The results indicate that the mean calculated/measured dry deposition flux ratios obtained using the model of Noll et al. (2010) for 2.5 µm particles and metallic elements (Cu, Cr, Cd, and Pb) in ambient air were all less than one in all seasons. The mean calculated/measured dry deposition flux ratios obtained using the model of Noll et al. (2010) for particles and metallic elements (Cu, Cr, Cd, and Pb) in ambient air were more than one in summer and autumn for particles of all sizes of interest. Finally, the mean calculated/measured dry deposition flux ratios that were obtained using the model of Noll et al. (2010) for metallic elements (Cu, Cr, Cd, Zn, and Pb) reflected the fact that all dry deposition fluxes were underestimated in the winter and spring for all particle sizes of interest.

Atmospheric total arsenic (As), (As3+) and (As5+) pollutants study in central Taiwan

This investigation measures the concentrations of arsenic (As), (As3+ ), (As5+) in total suspended particles (TSP) and dry deposits at five characteristic sampling sites in central Taiwan during the years 2009–2010, and identifies their seasonal variations. The investigation was performed in region in which a science park, transportation, waste incineration facility, fossil fuel combusting steel factory, electronics factory, plastic factory, chemical factory and Taichung Thermal Power Plant (TTPP) are located. The Bei-shi sampling station and He-mei town sampling station were located in, an area of heavy transportation. The Quan-xing sampling station was close to an electronics factory and a fossil fuel combusting steel factory. The As for Chang-Hua sampling station was located at the chemical factory. Finally, the Gao-Mei wetland sampling station was close to a waste incineration; they were characterized as a waste incineration plant and TTPP. The highest average concentrations of arsenic in TSP were found at Quan-xing (industrial) and the lowest were found at He-mei (residential). The average amounts of dry deposited arsenic (As), (As3+ ) and (As5+) were highest at the Quan-xing (industrial) site and lowest at the Gao-mei (wetland) site. The average seasonal concentrations of (As), (As3+ ) and (As5+) in TSP and the average dry deposited amounts were highest in the autumn and lowest in the summer at five sampling sites.

Characteristic Study of Ambient Air Total Gaseous Mercury (TGM) Concentrations During Rainy and Non-Rainy Periods at a Traffic Site in Taiwan

This investigation studied the concentrations of ambient air total gaseous mercury (TGM) during the rainy periods at the Hung-Kuang traffic sampling site in central Taiwan from May 26 to June 16, 2014. The results were compared with those of a previous study for ambient air TGM during non-rainy daytime and nighttime periods at the Hung-Kuang traffic sampling site, which was conducted during March 21 to July 20, 2012. The observed mean concentration of ambient air TGM was 1.16 ng/m3 during the rainy periods at the Hung-Kuang traffic sampling site. The mean ambient air TGM concentrations were higher in the non-rainy sampling period in daytime than in the rainy sampling period from this study. The mean ratio of non-rainy sampling period in daytime to that of rainy sampling period for ambient air TGM were 3.15. Furthermore, the mean ambient air TGM concentrations were higher in the non-rainy sampling period in nighttime in than in the rainy sampling period for this study. The mean rations for non-rainy sampling period in nighttime to that of the rainy sampling period for ambient air TGM were 2.70. The results obtained in this study also revealed that the ambient air TGM concentrations during the rainy period had the lowest concentrations when compared with the other sampling sites in other world regions.

Ambient air metallic pollutant study at HAF areas during 2013–2014

This study characterized diurnal variations of the total suspended particulate (TSP) concentrations, dry deposition flux and dry deposition velocity of metallic elements at Taichung Harbor (Harbor), Gong Ming Junior High School (Airport) and Sha lu Farmland (Farmland) sampling sites in central Taiwan between August, 2013 and July, 2014 in this study. The result indicated that: 1) the ambient air particulate concentrations, dry depositions were displayed as Harbor>Farmland>Airport during the day time sampling period. However, dry deposition velocities were shown as Airport>Harbor>Farmland for this study. 2) The ambient air particulate concentrations, dry depositions were displayed as Airport>Harbor>Farmland during the night time sampling period. However, dry deposition velocities were shown as Farmland>Harbor>Airport for this study. 3) The metallic element Zn has the average highest concentrations at Airport, Harbor and Farmland among all the metallic elements during the day time sampling period in this study. 4) There were significant differences for the metallic elements (Cr, Cu, Zn and Pb) in dry depositions at these three characteristic sampling sites (HAF) for the night time sampling period. The only exception is metallic element Cd. It displayed that there were no significant differences for the metallic element Cd at the Airport and Farmland sampling sites during the night time sampling period. 5) The average highest values for the metallic element Cu in TSP among the three characteristic sampling sites occurred during the fall and winter seasons for this study. As for the dry depositions, the average highest values in dry deposition among the three characteristic sampling sites occurred during the spring and summer seasons for this study. 6) The average highest values for the metallic element Cd in TSP among the three characteristic sampling sites occurred during the spring and summer seasons for this study. As for the dry depositions, the average highest values in dry deposition among the three characteristic sampling sites occurred during fall and winter for this study.

Particulates and Metallic Elements Monitoring at Two Sampling Sites (Harbor, Airport) in Taiwan

This study characterized the dry deposition flux and dry deposition velocity (Vd) of metallic elements attached on particulate matter. Specifically, large particles (>10 μm), coarse particles (10 μm∼2.5 μm), and fine particles (<2.5 μm) were studied at the Gong Ming Junior High School (Taichung Airport) and Taichung Harbor sampling sites in central Taiwan. Ambient air samples were collected to determine total suspended particulate matter (TSP), dry deposition plate (DDP), Vd, coarse particulate matter (PM2.5–10) and fine particulate matter (PM2.5), and metallic elements concentrations at the Airport and Taichung Harbor sites between June 17, 2013, and November 14, 2013. The results revealed that the average TSP, DDP, Vd, PM2.5–10, and PM2.5 particulate at the Airport were 54.55 (μg/m3), 902.25 (μg/m2-min), 17.11 (m/sec), 0.003 (μg/m3), and 0.010 (μg/m3), respectively; while these values at Taichung Harbor were 63.66 (μg/m3), 539.69 (μg/m2-min), 9.94 (m/sec), 0.003 (μg/m3), and 0.014 (μg/m3), respectively. In addition, the results showed that the average Cu and Pb concentrations were higher than Cr, Ni, and Cd for both the airport and harbor sampling sites. Furthermore, Cr, N, Cu, Cd, and Pb had the highest average concentrations versus those reported for other study areas, with one exception: The results obtained in Kacanik, Kosovo, during 2005. The average metallic elements concentrations order was Cu > Pb > Cr > Ni > Cd.

Comparisons of annual ambient air pollutant concentrations and dry deposition flux variations for day and nighttime in middle Taiwan

This study monitored ambient air particles and the metallic elements Cu, Cr, Cd, Pb, and Zn in total suspended particulate (TSP) concentrations and dry deposition during the day and nighttime sampling period at a traffic sampling site in central Taiwan from 2012 March to 2013 February. The dry deposition flux ratios and seasonal concentration variations of ambient air particles and these metallic elements are also discussed. The results indicate that for all the elements, except for Zn, the highest average concentrations in TSP occurred in the spring and summer, while the lowest average was in the fall and winter for both day and nighttime sampling periods.

Heavy Metal Pollution in Surface Soils of Five Characteristic Sampling Sites in Central Taiwan

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.

Temporal variability in atmospheric Hg released from natural and anthropogenic sources in central Taiwan

From September 2011 to February 2012, ambient air particulate and particulate-bound mercury [Hg(p)] concentrations were measured, together with dry deposition using a cold vapor atomic fluorescence spectrometry (CVAFS) analyser, at two characteristic sampling sites in central Taiwan. Results from the sampling site at Westin Park indicated that the lowest particulate dry deposition and lowest average particulate concentrations in total suspended particles (TSP) occurred in September (29.70±7.47 μ g m−2×min) and February (34.38±13.60 ng m−3), respectively. Moreover, results from the Gung-Ming junior high school (airport) site, showed that the highest average particulate dry deposition and average highest particulate concentrations in TSP occurred in February (156.76±30.36 μ g m−2×min) and January (125.49±9.51 ng m−3), respectively, during the winter. The Dragon Steel Plant and Han-Shian Aerospace Industrial Development Corporation were both nearby. These factors led to the high Hg(p) concentrations at Taichung Airport (TA) compared with Westin Park. Local large suspended particulates from heavy traffic were the main reason for the high average Hg(p) deposition at Westin Park compared with TA in this study.

Study of Ambient Air Particle-Bound As(p) and Hg(p) in Dry Deposition, Total Suspended Particulates (TSP) and Seasonal Variations in Central Taiwan

This study investigated the ambient air particle-bound As(p) and Hg(p) levels and compositions in dry deposition and total suspended particulates (TSP) at five sampling sites in Central Taiwan (suburban/coastal, downtown, residential, industrial and wetland) during the years of 2009 and 2010. The main industrial sources of studied metals in various investigated sites include: steel, electronic, plastic, and chemical industries, the Taichung thermal power plant (TTPP), fossil fuel combustion, a science park, transportation, and waste incineration. The samples were digested with hydrochloric acid (HCl) and nitric acid (HNO3), then they were analyzed for metals by ICP-MS. The mean As(p) levels in dry deposition were the highest at Quan-xing site (industrial) and the lowest at Chang-hua site (downtown). Moreover, the mean Hg(p) levels in dry deposition were the highest at Gao-mei site (wetland) and the lowest at He-mei site (residential). In addition, the mean As(p) levels in TSP were the highest at He-mei site (residential) and the lowest at Gao-mei site (wetland). The mean Hg(p) levels in TSP were the highest at Quan-xing site (industrial) and the lowest at Gao-mei site (wetland). Regarding seasonal variation, the lowest levels in dry deposition for both particles As(p) and Hg(p) occurred in spring and summer. Finally, the lowest levels of As(p) and Hg(p) in TSP were observed in fall and winter.

Seasonal Variations (Autumn, Winter, and Spring) of Atmospheric Particulate and Particulate-Bound Mercury Hg(p) at a Suburban/Coastal Area

From September 3, 2009, to March 5, 2010, the dry deposition, total suspended particulate (TSP) matter, coarse and fine particulates, and bound mercury (Hg[p]) in the atmosphere were investigated at Bei-Shi sampling site in central Taiwan. When using projection film as collection medium, the average ambient air particulates for day dry deposition fluxes and TSPs were 162.09 ± 97.69 (μg/(min/cm2)) and 78.71 ± 34.42 (μg/m3), respectively. The average fine particulate matter (PM2.5) and coarse particulate matter (PM2.5–10) were 20.5 ± 6.30 μgm−3 and 11.2 ± 4.44 μg m−3, respectively. Average atmospheric particulates Hg(p) in dry depositions, TSPs, PM2.5−10, and PM2.5were 0.156 ± 0.082 ng/m2*min, 0.07 ± 0.036 ng/m3, 0.011 ± 0.006 ng/m3,and 0.007 ± 0.005, respectively. The average compositions of atmospheric bound Hg Hg(p) in dry depositions, TSPs, PM2.5−10 and PM2.5 were 1.02, 36.8, 4.16 and 2.821, respectively. Also, the highest composition for particulate Hg(p) in TSP was observed in spring (50.74 ng/g), and the highest composition for particulate Hg(p) in PM2.5 occurred in autumn (3.11 ng/g). However, the highest composition for particulate Hg(p) in PM2.5−10 occurred in winter (4.67 ng/g). In what concerns particulate Hg(p) in TSP, the values were all less than those from previous studies (Wang et al., 2006). Related to Hg(p) in PM2.5, the values were also all less than those from previous studies (Tsai et al. 2003; Marsik et al. 2007). In what concerns Hg(p) in PM2.5−10, the values were all less than those of previous studies (Marsik et al. 2007). The data presented in this communication provides information that may be useful in forensic investigations of Hg environmental releases.

Delineating the hazard zone of multiple soil pollutants by multivariate indicator kriging and conditioned Latin hypercube sampling

Soil pollution delineation is a difficult task because there may be multiple pollution sources and complex transport schemes. In this study, four heavy-metal concentrations, namely Cr, Cu, Ni, and Zn, were collected at 1082 sampling sites in central Taiwan. Conditioned Latin Hypercube Sampling (cLHS) is used to determine the most cost-effective sampling strategies for long-term monitoring of multiple heavy metals. Then, the study estimates the probability of multiple hazardous heavy metals using multiple-variable indicator kriging (MVIK) based on sufficient cLHS samples. The results suggest that heavy-metal sampling patterns, including the size and configuration, affect the spatial distribution of probable hazards, especially when the sample size is small. Unlikely random sampling, the cLHS method replicates the variability and distribution of variables. In this study, an area is defined as a hazard zone if the amount of any heavy metal exceeds the corresponding regulatory threshold. The heavy-metal delineations (e.g., where the MVIK hazard probability exceeds 0.85) cover over 20% of the study area and correlate highly with the locations of industrial plants and irrigation systems in the area. Hence, MVIK coupled with cLHS provides a way to assess the presence of multiple hazards efficiently and effectively in future monitoring and environmental management projects.

Ambient Air Particulates and Related Ionic Species Study at Taichung Airport, Taiwan

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 dominant factor responsible for this result for the traffic-sampling site. The results also reflected that the water-soluble ionic species in the coarse particulates occupied the major portions except for the ionic species of Na+ and Mg2 + at the Taichung airport sampling site in central Taiwan. Additionally, the results indicated that the sulfate has the highest average composition compared with the other ionic species in TSP and PM2.5 at this airport sampling site. Such information may be useful in forensic investigations at the studied site.

Atmospheric Pollution Caused by Particulate Metals in Central Taiwan

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 for all particle sizes. Both Mn and Pb concentrations resemble each other throughout all particle sizes. Results of this study further demonstrate that average TSP or PM10 concentrations measured in this study were less than Taiwan Environmental Protection Agency standard.

Ambient air particulates, metallic elements, dry deposition and concentrations at Taichung Airport, Taiwan

The characterization of water-soluble species of dry deposition flux, total suspended particulates (TSPs), fine particles (particle matter with aerodynamic diameters < 2.5 μm (PM 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.