An Assessment of Source Contributions to Ambient Aerosols in Central Taiwan

Abstract

Ambient aerosols were sampled at three selected sites in the coastal region of central Taiwan to obtain composition data for use in receptor modeling. All the samples were analyzed for 20 elements with an x&#x0002D;ray fluorescence spectrometer. The mass percentage of sulfates in particle samples was determined by ion chromatography, and mass percentages of elemental carbon (EC) and organic carbon (OC) were determined by an elemental analyzer. Because the three sampling sites were located within 25 km of each other, the average chemical compositions were similar for particle samples taken at the three sites on the same day. However, the variation in composition from day to day was significantly influenced by wind direction and change in local sources, such as the burning of agricultural wastes. The abundant species in the coarse fraction (2.5&#x0002D;10 µm) were Al (0.5&#x0002D;4.0 µg/m), Cl (0.1&#x0002D;4.8 µg/m), Ca (0.2&#x0002D;3.4 µg/m), Fe (0.2&#x0002D;2.8 µg/ m), and K (0.1&#x0002D;1.4 µg/m), while the abundant species in the fine fraction (<2.5 µm) were S (0.3&#x0002D;3.5 µg/m), Cl (0.01&#x0002D;1.9 µg/ m), K (0.04&#x0002D;0.98 µg/m), organic carbon (0.01&#x0002D;10.5 µg/m), elemental carbon (0&#x0002D;10.7 µg/m), and sulfates (1.2&#x0002D;15.7 µg/m). Calculations for source apportionment were carried out using the CMB7 software developed by the U.S. Environmental Protection Agency (EPA). The main sources for the coarse fraction of ambient aerosols in the region were found to be marine aerosol, coal and fuel oil combustion, burning of agricultural wastes, and paved road dust. The main sources for the fine fraction were burning of agricultural wastes, diesel exhaust, coal and oil combustion, and sulfates. Source apportionment for the fine fraction was relatively sensitive to the types of sources selected for calculations and the compositions of the sources. The problem can be ameliorated by careful examination of possible sources and by use of local source profiles.

Seasonal trends in chemical composition of aerosols at a tropical coastal site of India

“…An average mass loading of 85 to 250 μ g m −3 has been reported over the industrialized coastal regions along the west coast of India [ Khemani et al , 1994]. Similar investigations at coastal sites of Taiwan showed a seasonal average concentration of PM 10 in the range 37 to 93 μ g m −3 [ Chen et al , 1997; Tsai and Cheng , 1999; Chio et al , 2004] and a background PM 10 level of 23 μ g m −3 has been reported over the coastal sites in Spain [ Salvador et al , 2007]. These values are comparable to that observed at Trivandrum.…”

Combustion Aerosols: Factors Governing Their Size and Composition and Implications to Human Health

“…For example, in urban areas in Taiwan, PM 2.5 was found to be as high as 80-90% of PM 10 , 302 and combustion was found to be a major source of both the coarse and fine PM. 303 Likewise, particles larger than 2.5 µm, or even larger than 0.5 µm, are rare in the central European urban environment. 304 The combination of particle size and chemical composition data provides insights into the sources.…”

Size-dependent particulate matter indoor/outdoor relationships for a wind-induced naturally ventilated airspace

“…As most time of 70 -90% is spend indoors, information on the indoor and outdoor relationships of PM concentrations is important. Indoor PM attributable to the outdoor air in urban/suburban residence houses has been the most serious indoor air pollution in Taiwan region [8][9][10][11][12][13][14]. In the indoor environment, the removal of entrained outdoor PM occurs through ventilation and deposition.…”