Abstract:
Screening medicinal plants suitable for growth in abandoned mining areas and evaluating their heavy metal enrichment ability and medicinal risks can provide the scientific basis for reducing the risk of heavy metal pollution in mining areas and improving land use efficiency. Nine dominant medicinal plants naturally growing at the top of the slope of a mining area in Henan Province were selected, and the whole plants and rhizosphere soil of 0-10 cm were collected. Using transport coefficient, bioenrichment coefficient, hazard quotient method and human health risk assessment model, the enrichment and transfer characteristics of each plant to the nine heavy metals were analyzed, and the potential health risks of medicinal plants to the human body were studied. The results showed that the proportion of available Cd and As in the rhizosphere soil was more than 20%, indicating a moderate risk. The contents of As and Cu were higher in
Conyza canadensis; the contents of Cr and Ni were higher in
Imperata cylindrica,
Conyza canadensis and
Setaira viridis; the contents of Pb were higher in
Imperata cylindrica,
Conyza canadensis and
Lonicera japonica.
Artemisia argyi had a strong enrichment ability of Cr, and
Lonicera japonica had a strong adsorption ability of Cd, As, Cu, Pb, Hg, Ag and other elements in the soil. At the same time,
Artemisia argyi and
Lonicera japonica had a low degree of harm to the human body.
Conyza canadensis and
Miscanthus floridulus had a strong adsorption and transport ability of Cd, As, Cu, Pb, Hg, Ag and other heavy metals in soil, but they had great risks to human health.
Salsola collina and
Rhus chinensis had a weak adsorption and transport ability of heavy metals such as Cd, As, Cu, Pb, Hg, Ag, and they were tolerant to heavy metals, so they belonged to plants with low accumulation of heavy metals. In the future research and ecological construction, it was necessary to select suitable plants for cultivation and restoration for specific purposes.