Evaluating health hazards of harmful metals in roadway dust particles finer than 100 μm

Abstract

Pollution degrees and health hazards of harmful metals in roadway dust particles finer than 100 μm in various functional areas in Xi’an, China were investigated in our study exploring the impact of land use methods on the environment. X-ray fluorescence spectrometry was used to measure the content of harmful metals, and their pollution degrees were assessed by using the geoaccumulation index and Nemerow synthetic pollution index. The health risks of harmful metals to local residents were judged using the U.S. EPA health risk model. The present study reveals that Co, Cr, Pb, Cu, and Zn in the samples were 2.1-6.3, 1.9-4.8, 2.1-9.7, 1.1-4.6, and 0.9-13.0 times the corresponding background contents of local soil, respectively. Due to the influence of local land use and the diversity of sources, harmful metals in the various functional areas have different variation characteristics. The assessment results show that Ni, Mn, and V were unpolluted, while Co, Cr, Pb, Cu, and Zn presented pollution in different degrees. The analyzed harmful metals were moderately polluted in park and traffic areas, while in residential and educational areas were heavily polluted. The non-carcinogenic hazards of all measured harmful metals were within the safe range, and the cancer hazards of Co, Cr, and Ni were in the acceptable range.