Rehman Abdul, Liu Guijian, Yousaf Balal, Ahmed Rafay, Rashid Muhammad Saqib, Irshad Samina, Shakoor Awais, Farooq Muhammad Raza
CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China; State Key Laboratory of Loess and Quaternary Geology, Institute of Earth Environment, The Chinese Academy of Sciences, Xi'an, Shaanxi, 710075, China.
CAS-Key Laboratory of Crust-Mantle Materials and the Environments, School of Earth and Space Sciences, University of Science and Technology of China, Hefei, 230026, PR China.
Environ Res. 2021 May;196:110427. doi: 10.1016/j.envres.2020.110427. Epub 2020 Nov 19.
Interior settled dust is one of the greatest threats of potentially toxic metal(oid)s (PTMs) exposure to the children, especially in the school environment. Therefore, it is more worthy of having in-depth knowledge of compositional characteristics of school dust. Forty schools were selected of Lahore city for dust sampling. The school dust was analyzed to determine the PTMs (As, Cd, Cr, Cu, Ge, Mo, Ni, Pb, Sb, Sn, Sr, V, and Zn) concentrations using ICP-MS. The morphological characteristics, PTMs speciation, and mineralogy of school dust were examined using SEM with EDS, XPS, and XRD, respectively. Moreover, the geo-accumulation index (I), potential ecological risk index (PERI), and multivariate statistical analysis were employed to assess the pollution levels, ecological risk, and source identification of PTMs, respectively. The I indicated a heavily-extreme pollution level of Cd (I = 4.92), moderate-heavy pollution of Zn (I = 3.22), and Pb (I = 2.78), and slight-moderate pollution of Cr (I = 1.62), and Cu (I = 1.53). The ecological risk has been found extremely high for Cd and moderately high for Pb and As, while potential ecological risk found extremely high posed by cumulatively all selected PTMs. Multivariate statistical analysis showed that sources of PTMs comprise of natural processes as well as several anthropogenic processes like vehicular emissions, agricultural and industrial activities. The SEM, XRD, and XPS analyses demonstrated the presence of airborne particles and PTMs containing minerals with several toxic chemical species in school dust. This study can help to develop strategies to reduce school indoor pollution and hence to establish an eco-friendly learning environment for children.
室内沉降灰尘是儿童接触潜在有毒金属（类金属）的最大威胁之一，尤其是在学校环境中。因此，更有必要深入了解学校灰尘的成分特征。在拉合尔市选择了40所学校进行灰尘采样。使用电感耦合等离子体质谱仪（ICP-MS）分析学校灰尘，以确定潜在有毒金属（砷、镉、铬、铜、锗、钼、镍、铅、锑、锡、锶、钒和锌）的浓度。分别使用带有能谱仪（EDS）的扫描电子显微镜（SEM）、X射线光电子能谱（XPS）和X射线衍射仪（XRD）检测学校灰尘的形态特征、潜在有毒金属的形态和矿物学。此外，还采用地累积指数（I）、潜在生态风险指数（PERI）和多元统计分析分别评估潜在有毒金属的污染水平、生态风险和来源识别。地累积指数表明镉处于重度至极重污染水平（I = 4.92），锌和铅处于中度至重度污染水平（I = 3.22和I = 2.78），铬和铜处于轻度至中度污染水平（I = 1.62和I = 1.53）。已发现镉的生态风险极高，铅和砷的生态风险为中度偏高，而所有选定潜在有毒金属累积造成的潜在生态风险极高。多元统计分析表明，潜在有毒金属的来源包括自然过程以及车辆排放、农业和工业活动等几种人为过程。扫描电子显微镜、X射线衍射仪和X射线光电子能谱分析表明，学校灰尘中存在空气传播颗粒和含有多种有毒化学物质的含潜在有毒金属矿物。本研究有助于制定减少学校室内污染的策略，从而为儿童建立一个生态友好的学习环境。
