dc.description.abstract | Taoyuan is a metropolitan city located in the Northern Taiwan that contains five industrial parks and an international airport, making it a leading industrial and commercial center. However, such industrialization and developments in transportation have resulted in elevated levels of hazardous suspended particles observed in the ambient air of this city. Among these airborne pollutants, polycyclic aromatic hydrocarbons (PAHs), a group of compounds that are chararacterized with high molecular weights, high boiling as well as melting points, and extrely low solubility in water, are of particular concern because several of the PAHs have been considered as persistant organic pollatants and endocrine disruptors. Nonetheless, littlle is known about the distribution and composition of the airborne PAHs that can be representative of the local conditions in Taiwan. Given that having this information would improve the management on the exposure risk of the sensitive receptors (such as children and elderly persons) to PAHs, ambient air, including both gasous- and particulate-pahses, of the elementary schools situated in the neighboring area of the Taoyuan Airport were sampled during the summers and winters of the years 2013 to 2015 using a large flow volume sampling apparatus, and analyzed for the specific nineteen PAH congeners using the gas chromatography-mass spectrometry (GC/MS) method. Results showed that the total levels of PAHs ranged from 44 to 147 ng/m3 (with 76 ng/m3 as the averaged concentration), 89 to 264 ng/m3 (with averaged 137 ng/m3), 218 to 370 ng/m3 (with ageraged 290 ng/m3), and 45 to 128 ng/m3 (with the mean concentration of 73 ng/m3) for the samples obtained from the first (in July 2013), second (in January 2014), third (in July 2014), and fourth (in January 2015) sampling campaigns, respectively. When examining the data closely, it is noted that while the concentrations of PAHs in the winter samples of the first year appeared higher than those in the summer of the same year, an opposite trend was observed in the third year (i.e., the summer had higher PAH levels than the winter), which seemed to contradict the theoretical notion that pollutions are generally considered weaker in winter than in summer due to the occurrence of a relatively low altitude of the mixling layer, poor diffusioin conditions, and slower photo-chemical reations in winter. We speculated that this might have been resulted from some uncertainty or unknown factors. Regardless, our data indicated that the major compoenents of the PAHs in the ambient air of the three studied elementary schools were Naphthalene (Nap) and 2-Metrylnaphthalene (2-MNap). While the toxicity of these two compounds is not considered as strong as that of Benzo(a)pyrene (Bap), potential problems of biological accumulation resulted from these two compounds can not be ignored. Together, these results not only can be used for the establishment of the requlatory PAH concentrations in the future, but can also be regarded specifically as the reference (or baseline) ambient air quality data for Taoyuan Aerotropolis. | en_US |