||Fine particles (PM2.5) are particles suspended in the air, with aerodynamic diameter less than or equal to 2.5 μm, which has become the largest challenge for air pollution abatement. Although Taiwan EPA has already categorized PM2.5 into Air Quality Standard with national control strategies and projects, but Kaohsiung City is currently the most polluted area in Taiwan, thus significant improvement on PM2.5 is required, and therefore it is necessary to put forward advanced control strategies that are more suitable for local characteristics.|
First of all, this research analyzed previous monitoring data from EPA’s ambient air quality automatic monitoring stations and Southern Taiwan super monitoring station. Following the EPA’s newly announced fine particulate manual sampling and analytical methods, this study conducted the sampling and analysis of PM2.5 for continuous three months at two sites, to identify the chemical composition of fine particulate in Kaohsiung. The results could assist in developing feasible control strategies with local source characteristics.
Based on EPA’s long term monitoring data measured at stations in Kaohsiung City showed that the yearly average concentration of PM2.5 ranged from 30.75 μg/m3 to 52.92 μg/m3, and PM2.5 accounted for 57~62% of PM10, showing that fine particulate is one of major air pollutants in Kaohsiung City. Additionally, the Southern Taiwan super monitoring station showed that the main species in Kaohsiung's fine particulate（PM2.5）included SO42-, NO3-, OC, and EC. Particularly, SO42- accounted for approximately 26%~28% of soluble ionic species. On the other hand, the manual sampling results also showed that SO42- has the highest concentration, accounting for 37.48% and 37.86% of soluble ionic species at EPB station and NSYSU station. Metal element composition of PM2.5, respectively, accounting for 10.17%, 10.43%, of which K, Mg, Ca, Al, etc. are the highest proportion.
Sulfur dioxide is the precursor of fine particles, and Kaohsiung City is the most polluted area with the highest concentration of sulfur dioxide. Therefore, this research showed that the best strategy for reducing ambient fine particles in Kaohsiung City is to reduce the concentration of sulfur dioxide in the air.
This research considered the sulfur oxide emission mainly came from stationary sources, accounting for about 90.72% of city’s total emission; thus, we suggested three control strategies for reducing PM2.5 concentration in Kaohsiung City: (1) reducing the sulfur content of fuel oil, (2) tightening local sulfur dioxide standard, and (3) increasing the sulfur oxides air pollution fee rate. We can apply the strategies with precedent and lower administration cost to lower the concentration of sulfur dioxide in the air, thus to improve the current PM2.5 pollution status in Kaohsiung City.