School of Chemical Engineering, Lanzhou City University, Lanzhou 730070, China; Provincial Key Laboratory of Gansu Higher Education for City Environmental Pollution Control, School of Chemical Engineering, Lanzhou City University, Lanzhou 730070, China.
Gansu Academy of Environmental Science, Lanzhou 730030, China.
Ecotoxicol Environ Saf. 2022 Mar 15;233:113353. doi: 10.1016/j.ecoenv.2022.113353. Epub 2022 Feb 28.
The deposition is an important process of microplastics transporting from atmosphere to water and soil. But the spatial and temporal distribution of microplastics in urban atmospheric deposition and its influencing factors are poorly understood. The current study investigated the possible sources, spatial and temporal distribution, and potential ecological risk of microplastics in deposition from the valley basin of Lanzhou city during the COVID-19 pandemic (from February to August, 2020). The deposition flux of microplastics was 353.83 n m d. Most plastic samples were small sized (50～500 µm) and transparent. The dominant chemical composition and shapes were PET, fragments and fibers, respectively. A modified method was conducted to identify the sources of microplastics, and the local sources were suggested as the main possible sources. The distribution of microplastics investigated through the inverse distance weight interpolation showed spatial variation and temporal differentiation which was dominated by the human activity. The rainfall also affected the temporal distribution. The preliminary assessment indicated higher potential ecological risk of microplastics in deposition. This study suggested the dominant effect of human activity on the source and distribution of atmospheric microplastic deposition in city.
沉积作用是微塑料从大气向水和土壤迁移的一个重要过程。然而，城市大气沉降中微塑料的时空分布及其影响因素仍不清楚。本研究在 COVID-19 大流行期间（2020 年 2 月至 8 月）调查了兰州市山谷盆地大气沉降中微塑料的可能来源、时空分布和潜在生态风险。微塑料的沉积通量为 353.83 n m d。大多数塑料样本的尺寸较小（50～500 μm）且呈透明状。主要的化学成分和形状分别为 PET、碎片和纤维。采用改进的方法对微塑料的来源进行了识别，结果表明本地源是主要的可能来源。通过反距离权重插值法对微塑料的分布进行研究，结果表明存在空间变化和时间差异，这主要受人类活动的影响。降雨也影响了时间分布。初步评估表明，沉积中微塑料的潜在生态风险较高。本研究表明，人类活动对城市大气微塑料沉积的来源和分布具有主导作用。
