[Current Pollution Status， Health Risk Assessment and Source Apportionment of Heavy Metals in Vegetable Soil in...

Understanding the status and sources of vegetable soil heavy metals pollution has great significance for soil protection and vegetable production safety. In this study， the contents of five heavy metals， Cr， Cu， Zn， As， and Cd， were collected and determined in 151 surface vegetable soil samples from the typical vegetable soil of Tongliang District. The heavy metals pollution degree was evaluated by means of the geoaccumulation index， enrichment factor， and potential ecological risk index. The carcinogenic and non-carcinogenic risks of the heavy metals were evaluated using the health risk model. The sources of the heavy metals in the topsoil were analyzed by correlation analysis， principal component analysis （PCA）， cluster analysis， absolute principal component score-multiple linear regression （APCS-MLR）， and other qualitative and quantitative methods. The results showed that the average contents of Cu， Zn， and As in the vegetable garden soils of Tongliang District exceed background values， being 1.78， 1.71， and 3.32 times higher， respectively. The contents of Cu， Zn， As， and Cd in 15.89%， 11.26%， 4.64%， and 3.97% of the soil sites exceeded the risk screening values， respectively. Enrichment factor analysis classified As as light pollution， with 62.62% of the soil samples showing light pollution and 20.56% showing moderate pollution levels. The geoaccumulation index analysis revealed that As is at a moderate pollution level， while Cu and Zn fall into the light-to-moderate pollution category. The potential ecological risk assessment suggested that the study area primarily faces moderate ecological hazards， with As contributing 51.66% of the ecological risk. Source apportionment analysis revealed that the average contributions of agricultural-natural sources， atmospheric deposition， and unknown sources are 66.75%， 22.06%， and 11.19%， respectively. The health risk assessment further revealed that the non-carcinogenic risk quotient for As exceeds 1， indicating potential non-carcinogenic risks for both adults and children. Thus， there is an urgent need for effective management and remediation strategies to address As contamination and ensure the safety of vegetable production in the region.