The Need to Improve Riparian Forests Management in Uranium Mining Areas Based on Assessment of Heavy Metal and Uranium Contamination

Abstract

Environmental contamination caused by uranium mining is becoming a worldwide issuedue to its negative impact on the environment. The aim of this study is to evaluate the contaminationlevels of riparian forest stands and their interaction with pollutants on the example of two localitieswith long and short-term uranium mining closure. Notably high Cu content, which exceeded thelower range of the toxicity limit in 50–75% of the cases, was detected in the leaves. Increased U contentalso represents a potential risk. As both of the elements have a negative effect particularly on the rootsystem, it can be assumed that the soil-stabilizing and water erosion-reducing functions of the standsmay be reduced. Extremely high U content (51.8 mg/kg DA) in the leaves ofAesculus hippocastanumL. indicates its potential for phytoremediation. Significantly higher U content determined at thelocality with the long-term closure of mining was probably caused by the instauration of the shallowhydrogeological circulation after mine inundation. Strong correlation between U and Pb suggestsidentical trend of their uptake and accumulation by plants. A significant dependence of the level ofcontamination on the distance from its source was not demonstrated. Therefore, the management ofmining areas should focus on the protection of riparian forest, which can through its stabilizing anderosion-reducing functions and through suitable species composition effectively prevent spreadingof contamination.Environmental contamination caused by uranium mining is becoming a worldwide issuedue to its negative impact on the environment. The aim of this study is to evaluate the contaminationlevels of riparian forest stands and their interaction with pollutants on the example of two localitieswith long and short-term uranium mining closure. Notably high Cu content, which exceeded thelower range of the toxicity limit in 50–75% of the cases, was detected in the leaves. Increased U contentalso represents a potential risk. As both of the elements have a negative effect particularly on the rootsystem, it can be assumed that the soil-stabilizing and water erosion-reducing functions of the standsmay be reduced. Extremely high U content (51.8 mg/kg DA) in the leaves ofAesculus hippocastanumL. indicates its potential for phytoremediation. Significantly higher U content determined at thelocality with the long-term closure of mining was probably caused by the instauration of the shallowhydrogeological circulation after mine inundation. Strong correlation between U and Pb suggestsidentical trend of their uptake and accumulation by plants. A significant dependence of the level ofcontamination on the distance from its source was not demonstrated. Therefore, the management ofmining areas should focus on the protection of riparian forest, which can through its stabilizing anderosion-reducing functions and through suitable species composition effectively prevent spreadingof contamination.