It is crucial to investigate the chemical species that cause increases in PM_2.5 concentration and to quantitatively estimate source contributions to PM_2.5 in urban environments in order to establish strategies to control anthropogenic air pollution. In this study, measurements of 24-hr integrated PM_2.5 were performed for 1 year at an urban site in Gwangju, Korea. The collected samples were analyzed for organic and elemental carbon (OC and EC), water-soluble OC (WSOC), eight ionic species, and elemental species, which were used to estimate source contribution of PM_2.5 using a positive matrix factorization (PMF) model.

The dominant species that contributed to PM_2.5 during the study period was organic matter (OM), which accounted for 24% of PM_2.5. The major chemical species resulting in PM_2.5 pollution episodes (>24-hr Korean PM_2.5 standard of 35 μg/m³) depended on the season. For example, PM_2.5 increases in winter were strongly associated with increases in secondary nitrate and OM concentrations, while rapid increases in secondary sulfate concentration brought on summertime PM_2.5 increases.

A total of eight sources of PM_2.5 were identified using PMF analysis: secondary nitrate (26%), secondary sulfate (23%), traffic emissions (14%), metallurgical and smelting processes (11%), brake and tire wearing processes (9%), biomass burning emission (8%), crustal source (7%), and industrial sources (1%). The brake and tire wearing processes were a non-negligible contributor to total PM_2.5 at the study site, accounting for 7% of PM_2.5 in summer and 18% in fall. Metallurgical and smelting processes, which are highly enriched in elements such as Pb, Cu, As, Se, and Zn, were also found to be an important source of PM_2.5 at the study site, contributing 7% of PM_2.5 in summer and 14% in fall. Moreover, the total contribution of mobile-related emissions, such as vehicles and brake and tire wearing processes, to PM_2.5 ranged from 15.2% in summer to 40.0% in winter with an average of 23%. Overall, the results of this study suggest that control of mobile-related sources is crucial to reducing the high PM_2.5 levels in the Gwangju metropolitan area.

为了建立控制人为空气污染的策略，研究导致PM _2.5浓度增加的化学物质并定量估算源对PM _2.5的贡献至关重要。在这项研究中，在韩国光州的一个城市地点对一年中的24小时集成PM _2.5进行了测量。分析收集的样品中的有机碳和元素碳（OC和EC），水溶性OC（WSOC），八个离子物种和元素物种，这些元素用于通过正矩阵分解（PMF）估算PM _2.5的源贡献。模型。

在研究期间，造成PM _2.5的主要物种是有机物（OM），占PM _2.5的24％。导致PM _2.5污染发作的主要化学物质（大于24小时的韩国PM _2.5标准浓度为35μg/ m ³）取决于季节。例如，冬季PM _2.5的增加与次要硝酸盐和OM浓度的增加密切相关，而继发硫酸盐的迅速增加导致夏季PM _2.5的增加。

使用PMF分析确定了总共8种PM _2.5来源：硝酸根硝酸盐（26％），硫酸根硫酸盐（23％），交通排放量（14％），冶金和冶炼过程（11％），制动和轮胎磨损过程（ 9％），生物质燃烧排放量（8％），地壳源（7％）和工业源（1％）。制动和轮胎磨损过程对研究现场的总PM _2.5的贡献不可忽略，夏季占PM _2.5的7％，秋季占18％。冶金和冶炼过程中富含Pb，Cu，As，Se和Zn等元素，在研究现场也是PM _2.5的重要来源，占PM _2.5的7％。在夏季，在秋季下降14％。此外，与移动相关的排放（如车辆，刹车和轮胎磨损过程）对PM _2.5的总贡献从夏季的15.2％到冬季的40.0％不等，平均为23％。总体而言，这项研究的结果表明，控制移动相关源对于降低光州广域市的高PM _2.5水平至关重要。