Abstract：
This study examines for the first time the characteristics and human exposure of microplastics (MPs) in settled indoor dust in schools. An average of 195 MPs·g-1 of dust were detected in settled indoor composite dust samples from 28 schools in Shiraz. White-transparent microfibres with lengths 500-1000 μm were the most abundant type of MP found among the samples examined. Polyethylene terephthalate and polypropylene MPs were dominant across all types of MP found including microfibres. MPs had generally smooth morphology with sharp or regular edges which could have been released to the environment as primary MPs. Among all sampling sites, higher concentrations of MPs were found in the south and centre of the city. These were areas affected by high population density, high traffic load and high presence of industrial units and workshops. Principal Component Analysis (PCA) showed a positive strong correlation between sampling sites and MP physical characteristics. The PCA plots revealed that MP sheets and fragments were prevalent in sites in the North of Shiraz, whereas microfibres were mainly associated with sites in the South. The levels of MPs in the South of Shiraz were greater than in the rest of the country and the wind direction and topography were found to be important factors affecting the MP distribution observed. Compared to other population groups, elementary school students had relatively high exposure risk to MPs. This study reveals that microfibres are widespread in Shiraz\' schools and pose a high exposure risk to MPs for young students.
摘要：
这项研究首次研究了学校室内尘土中微塑料（MPs）的特征和人体暴露。在设拉子28所学校的室内复合粉尘样品中，平均检测到195MPs·g-1的粉尘。长度为500-1000μm的白色透明微纤维是在所检查的样品中发现的最丰富的MP类型。聚对苯二甲酸乙二醇酯和聚丙烯MP在包括微纤维在内的所有类型的MP中占主导地位。MPs通常具有光滑的形态,具有尖锐或规则的边缘,其可以作为主要MPs释放到环境中。在所有采样地点中，在城市的南部和中心发现了较高浓度的国会议员。这些是受高人口密度影响的地区，高交通负荷和高存在的工业单位和车间。主成分分析（PCA）显示采样点与MP物理特征之间呈正相关。PCA图显示，MP表和碎片在设拉子北部的地点很普遍，而微纤维主要与南部地区有关。设拉子南部的MP水平高于该国其他地区，发现风向和地形是影响观察到的MP分布的重要因素。与其他人群相比，小学生对国会议员的接触风险相对较高。这项研究表明，超细纤维在设拉子学校中普遍存在，并且对年轻学生的国会议员具有很高的暴露风险。
