RESUMO
In order to explore the pollution characteristicsï¼ ecological risksï¼ and pollution sources of heavy metals in farmland soils around typical factories in Hunan Provinceï¼ the content characteristics of eight heavy metals in farmland soils around fluoride factoriesï¼ leather factoriesï¼ and plating plants were analyzed. The geo-accumulation index and potential ecological risk index were used to evaluate the pollution and environmental risk of heavy metals. The correlation analysisï¼ hierarchical cluster analysisï¼ and principal component analysis were used to analyze the sources of heavy metals. The Monte-Carlo model was used to evaluate the probability risk of regional ecological risk. The results showed that the main pollution elements in the soil were Cd and Znï¼ and their mean values were 4.46 and 2.73 times the background valuesï¼ respectively. Zn was at a mild pollution level in the soil of the three typical factoriesï¼ and Cd was at a moderate pollution level in the whole fluoride factory. The pollution sources of heavy metals in the typical factories were mainly natural sourcesï¼ industrial activity sources ï¼industrial waste dischargeï¼ mineral miningï¼ and smelting activitiesï¼ï¼ traffic sourcesï¼ etc. The results of potential ecological risk assessment showed that the ecological risk of the fluoride factory was at a high risk levelï¼ and the ecological risk of the leather factory and plating plants was at a high risk level. Cd was the main contributing element. The results of Monte-Carlo probabilistic ecological risk assessment reduced the uncertainty of deterministic assessmentï¼ which could provide scientific basis for accurate risk management and control in the regions.