Analysis of lead contamination sources in roadside soil via the isotope tracing method

In addition to industrial contamination sources, road traffic sources are becoming major sources of potentially toxic elements (PTEs) contamination in soil. The PTEs contaminants generated during transport mainly include lead (Pb) and other elements. In this study, to clarify the sources of Pb in the roadside atmosphere and soil and their relative contributions, roadside atmospheric dustfall, sediment and soil samples were collected in industrial and nonindustrial areas, and the Pb isotope values of the samples were determined via inductively coupled plasmamass spectrometry (ICPMS). The sources of Pb in the roadside atmosphere and soil samples were quantified via isotope tracing. The results revealed that vehicle emissions contributed the most to Pb in the roadside atmosphere, followed by road sediment and natural atmospheric dustfall, with contributions ranging from 43.5 % to 48.9 %, 35.3-39.8 %, and 15.8-16.7 %, respectively. Roadside atmospheric dustfall contributed the most to Pb in roadside soil, followed by road sediment. Among these sources, roadside atmospheric dustfall and road sediment contributed 68.3-68.4 % and 31.6-31.7 %, respectively, in nonindustrial areas and 61.2-61.3 % and 38.7-38.8 %, respectively, in industrial areas. The results of this study provide a basis for preventing and controlling Pb pollution in roadside soils.