Heavy metal pollution and probabilistic risk assessment in soil of desert road shelterbelts in typical oasis cities in Northwest China.

The topic of this paper is the heavy metal pollution in desert road soil and the probability risk assessment of heavy metal pollution. The research topic adopts a quantitative analysis method to quantify the impact of soil heavy metal concentration and the contribution of soil heavy metal impact to human health risks. During the research process, surface soil collection was completed, with samples from two desert road protection forest belts in oasis cities. The assessment methods for heavy metal pollution levels include heavy metal migration factor, Nemero comprehensive pollution index, pollution index, and geochemical baseline value. The results confirm that there is a moderate risk of heavy metal pollution in the sample, but there is no overly obvious ecological risk. Zhongwei City has relatively severe Pb pollution, while Wuwei City has severe Cd pollution. Subsequently, based on Species Sensitivity Distribution as the basic support, the derivation and calculation of Predicted No Effect Concentration were completed, and the ecological risk was evaluated. The health risk assessment tools for different populations include health risk assessment models and Monte Carlo models. From the evaluation conclusion, the non-carcinogenic risk of Pb (adult: 99.98%; child: 99.98%) and As (adult: 54.28%; child: 98.11%) in the protective forest of Wuwei Desert is low, and the probability of carcinogenic risk is high. The results in Zhongwei are similar to those in Wuwei, both of which have a more serious health probability risk. From the derivation and calculation results, it can be seen that GB 36600-2018 (Soil Environmental Quality Standards) cannot protect species diversity well. The research conclusion can promote the analysis and control of environmental risks on desert highways from both theoretical and practical perspectives.