LAUSR

Roadside soils are regarded as the reservoir for the heavy metal pollution, which potentially lead to the ecosystem deterioration, as well as serious hazard to human health. The comprehensive investigation was conducted for the levels, relationship with soil properties and potential sources of heavy metals (Hg, Cu, Zn, Pb, Cd and Cr) in roadside soils in six cities (Changzhi, Jincheng, Yuncheng, Linfen, Xinzhou, Datong) of Shanxi Province, and the corresponding ecological risk and human health risk associated with the concentrations of heavy metals were addressed. Detecting the heavy metal concentrations of 112 roadside soil samples in the surveyed cities, the degree of heavy metals levels was in the decreasing order with Zn, Cu, Cr, Pb, Cd and Hg, which were higher than corresponding background values. The highest concentrations displayed in Changzhi. The results of Perason correlation analysis demonstrated that the positive correlation in varying degrees existed between soil properties such as electrical conductivity, total nitrogen, total phosphorus and total organic carbon with specific heavy metals and the negative correlations were observed for clay and EC. The anthropogenic sources related with traffic emissions and industrialization were the main sources of heavy metals in roadside soils according to principal component analysis. The ecological risk assessments were achieved by pollution index and potential risk index, indicating that the contamination of Hg was the most serious which posed the high risk to the ecosystems in the surveyed cities and the ecological risk in Changzhi ranked the top compared with other cities. For the human health risk assessment, the results demonstrated that the non-carcinogenic and carcinogenic risks were in the acceptable range in the surveyed cities. However, the higher health risks by heavy metals were exposed to children than adults, and the main exposure pathway was the soil ingestion. In addition, Changzhi was the city with the highest risks of non-carcinogenic and carcinogenic, and the main human health risks were posed by Cr contamination in roadside soil, which was different from the results of ecological risks. Both results of ecological and health risk assessment demonstrated that the higher risk exhibited in southern and southeastern cities than northern cities in Shanxi province.