Analysis of Critical Source of Potentially Harmful Elements in Urban Road Dust During Winter in Taiyuan Based on Multiple Attribute Decision Making Method

Abstract

In order to analyze the critical sources of potential harmful elements (PHEs) in road dust from Taiyuan during winter, 40 road dust samples were collected. The contents of PHEs, including As, Cd, Pb, Ni, Cr, Cu, and Zn, in the road dust samples were measured using inductively coupled plasma mass spectrometry and atomic fluorescence spectrometry. The ecological risks and human health risks posed by dust PHEs were assessed using NIRI and a health risk evaluation model recommended by USEPA, respectively. The sources of dust PHEs were identified by using the combination of principal component analysis and positive matrix factorization (PMF); the total PHE contents and the ecological risks and human health risks posed by PHEs in dust were apportioned to the PHE sources based on the PMF results; subsequently, the critical source of dust PHEs was determined using the multiple attribute decision making method (MADM). The results demonstrated that: 1 the average concentrations of As, Cd, Pb, Ni, Cr, Cu, and Zn were 17.92, 0.32, 69.10, 30.06, 107.74, 73.37, and 268.49 mg·kg-1, respectively, which were higher than the corresponding background values of soil in Taiyuan, indicating that the PHEs had accumulated in road dust; the mean value of NIRI was 63.86, demonstrating that PHEs in dust posed moderate risks, and the dust PHEs pollution was controllable. 2 Human health risk assessment indicated that exposure to PHEs in dust did not pose serious non-carcinogenic or carcinogenic risks. Ingestion was the most important pathway for exposure to PHEs in road dust that damages human health, and As and Cr have been found to pose the most risks among the seven PHEs. 3 The present study found three main sources of PHEs measured in the dust: natural, traffic, and industrial, which accounted for 35.95%, 40.25%, and 23.82% of the total concentrations of PHEs, respectively. 4 Industrial emissions contributed the least to the total PHEs contents in dust; however, the PHEs released from industrial sources caused relatively high risks, with the results of MADM indicating that industrial sources were the most critical source for dust PHEs. Our results indicated that the critical source identification of PHEs, which was determined to be the most pernicious source, could provide reference for subsequent pollution source control.