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The main purpose of this study was to monitor ambient air particles and metallic elements (Zn, Pb, Mg, and Ca) in total suspended particulates (TSP) concentrations and dry deposition. In addition, the calculated/measured dry depositions flux ratios of ambient air particles and metallic elements (Zn, Pb, Mg, and Ca) were also evaluated using Wood's model at Hung Kuang (traffic) site in Central Taiwan from years 2011 to 2012. The results indicated that: 1) the mean highest concentration for metallic element Zn occurred at 10 μm particle size during the daytime sampling period; 2) the mean highest concentration of metallic elements Mg occurred at 23 μm particle size during the nighttime sampling period; and 3) the mean highest concentration of metallic element Pb occurred at 20 μm particle size for the average sampling time of the daytime and nighttime sampling periods at this traffic sampling site. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Total gaseous mercury (TGM) concentration in ambient air, particulate-bound mercury concentrations and particulate-bound mercury contents in total suspended particles (TSP) from locations in Central Taiwan were measured and discussed relative to their ranges and potential sources. Meteorological conditions in terms of average temperature, wind direction, wind speed, and humidity were also monitored at a traffic sampling site in Sha-Lu central Taiwan from July 2011 to November 2011. The results revealed that the average concentrations of total gaseous mercury (TGM) and particulate-bound mercury in TSP were 8.73±5.53 (ng/m3) and 0.000164±0.00007 (ng/m3), respectively. The monthly average TGM concentrations were highest in July (17.50±4.79 ng/m3) and lowest in November (4.10±0.72 ng/m3). The monthly average particulate-bound mercury concentrations were highest in July (0.000293±0.00021 ng/m3) and lowest in November (0.000109±0.00002 ng/m3). The average particulate-bound mercury Hg(p) contents were 0.15 (ng/g), while the monthly average particulate-bound mercury contents were highest in July (0.26 ng/g) and lowest in November (0.11 ng/g). In summer, industrial activities, especially smelting activities, were an important source of atmospheric Hg (Fu et al., 2009). Therefore, high mercury concentrations were observed in July and August. Several main sources of Hg emissions have also been identified in the study area. [ABSTRACT FROM AUTHOR]

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-, SO42 -, 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, and 9.98 μ g/m3 in PM10. However, t-test results revealed that the concentrations of ionic species (Cl-, NO2-, NH4+, Mg2 +, and Ca2 +) in PM2.5 during the day did not differ significantly from those at night. T-test results revealed that the ionic species (NO3-, SO42 -, Na+, and K+) concentrations in PM2.5 during the day differ, significantly from those at night. The concentrations of ionic species (Cl-, NO2-, NO3-, and NH4+) in PM10 during the day did not differ significantly from those at night. The concentrations of ionic species (SO42 -, Na+, K+, Mg2 +, and Ca2 +) in PM10 during the day differed significantly from those at night. The concentration of Cl- in PM2.5 is negatively correlated (r = -0.62) with the temperature during the day at this site close to highway traffic. Furthermore, a comparison with previous results (Fang et al., 1999a) revealed that the average concentration of NO3- increased by 32% and 46% in PM2.5 and PM10, respectively, during the day. Average concentrations of NO3- were increased by 72% and 65% in PM2.5 and PM10, respectively, during the night. Average concentrations of SO42 - were decreased by 10% and 7% in PM2.5 and PM10, respectively, during the day. Finally, average concentrations of SO42 - were decreased by 72% and 62% in PM2.5 and PM10, respectively, during the night. This monitoring data may be helpful to establish baseline or background concentrations, which is essential for forensic investigations. [ABSTRACT FROM AUTHOR]