부산대학교 도서관

Objectives: Levels of atmospheric fine particulate matter (PM_(2.5)) may be affected by the traffic sources. This article explores correlations between the PM_(2.5) level and traffic sources in Yun-Chia-Nan area in Taiwan. Methods: Data regarding PM_(2.5) levels and motor vehicle density in 2015 were obtained from Environmental Protection Administration monitoring stations and Environmental Resource Database, respectively. The study area covers four southwestern districts of Taiwan: Yunlin County, Chiayi City, Chiayi County, and Tainan City. Mean, median, minimum, and maximum values for PM_(2.5) levels, meteorological variables, and motor vehicle densities were calculated. The relationship between PM_(2.5), meteorological variables, and motor vehicle density was estimated using the Spearman's rank correlation coefficient. A multiple linear regression model was used to explore the associations of PM_(2.5) with motor vehicle density. The study duration was January-December 2015. Results: In 2015, the annual mean PM_(2.5) level was 26.4 μg/m^3; PM_(2.5) levels were higher in the colder season (November-April; 35.0 μg/m^3) than in the hotter season (May-October; 17.8 μg/m^3). The motor vehicle densities were 380.1 car/km^2 and 734.8 motorcycle/km^2. The relationship between motor vehicle density and PM_(2.5) level was positive, but nonsignificant. Temperature was the major factor influencing the PM_(2.5) levels. Moreover, the effects of motor vehicle density on the PM_(2.5) level varied geographically: for every 1-car/km^2 increase, the PM_(2.5) level increased by 0.762, 0.362, 0.977, and 1.030 μg/m^3 in Tainan City, Chiayi City, Chiayi County, and Yunlin County, respectively. Conclusions: Temperature is the major factor influencing PM_(2.5) levels in Yun-Chia-Nan area in Taiwan. The effect of traffic sources on PM_(2.5) level might have geographic variation. Further relevant research is warranted.