Source identification of atmospheric microplastics (MPs) is crucial for the development of mitigation policies. Compared with wind directions or backward trajectories of air masses, the potential source contribution function (PSCF) analysis identifies more comprehensive sources of atmospheric particles. However, conducting PSCF analysis requires hourly pollutant concentration data, which cannot be met by the atmospheric MPs abundance obtained through commonly used methods. In this study, total suspended particles (TSP) samples were collected hourly and the concentrations of atmospheric polyethylene terephthalate (PET) were detected using a liquid chromatography-tandem mass spectrometry. Atmospheric concentrations of PET MPs were 112.9 ± 39.04 ng/m³ (average ± SD). Based on the hourly backward trajectories of air masses and the varied PET concentrations at the sampling site, potential sources of atmospheric PET were identified by PSCF analysis. The backward trajectory-based method indicates that atmospheric PET of the target site in this study primarily originates from dry farmlands. In comparison, both the residential areas and the dry farmlands were identified by PSCF as major sources of atmospheric PET at the receptor site. In contrast, both the backward-trajectory based method and PSCF analysis indicate that TSP mainly originates from the dry farmlands near the sampling site. This indicates that atmospheric PET in urban areas may have different sources from those of TSP, and PSCF is a suitable method for identifying sources of atmospheric PET.

中文翻译：

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潜在来源贡献函数与质谱检测相结合，用于确定大气中聚对苯二甲酸乙二醇酯的来源


确定大气中微塑料 （MP） 的来源对于制定缓解政策至关重要。与风向或气团的反向轨迹相比，潜在来源贡献函数 （PSCF） 分析确定了更全面的大气粒子来源。然而，进行 PSCF 分析需要每小时的污染物浓度数据，而通过常用方法获得的大气 MPS 丰度无法满足这些数据。在本研究中，每小时收集总悬浮颗粒 （TSP） 样品，并使用液相色谱-串联质谱法检测大气中聚对苯二甲酸乙二醇酯 （PET） 的浓度。PET MPs 的大气浓度为 112.9 ± 39.04 ng/m³（平均 ± SD）。根据气团每小时的反向轨迹和采样点不同的 PET 浓度，通过 PSCF 分析确定了大气 PET 的潜在来源。基于逆向轨迹的方法表明，本研究中目标地点的大气 PET 主要来自干燥的农田。相比之下，PSCF 将住宅区和旱地确定为受体位点大气 PET 的主要来源。相比之下，基于后向轨迹的方法和 PSCF 分析都表明 TSP 主要来源于采样点附近的干燥农田。这表明城市地区的大气 PET 可能与 TSP 的来源不同，而 PSCF 是识别大气 PET 来源的合适方法。