Evaluating potential phytoremediators to combat detrimental impacts of mining on biodiversity: a review focused in Africa

Abstract

Mining activities generate hazardous metal waste, impacting biodiversity, yet this linkage is overlooked in most developing countries. Phytoremediation has emerged as the most cost-efficient and eco-friendly technique for multielement remediation. However, the identification of suitable plants requires extensive laboratory testing, hindering its practical application, especially in developing African countries. Consequently, we conducted this review to evaluate the adverse impacts of mining on biodiversity in African countries and identify potential phytoremediators. We compiled information from articles available in various international databases and published by different publishers, based on selected search keywords. The review identified several mining operations, including topsoil removal, smelting and screening of iron ores, pit digging, excavation, drilling, blasting, chemical discharge, spillages and leakages, and improper disposal of solvents, as potential threats to biodiversity. A total of 146 phytoremediators were identified, including 78 natives of the African continent, comprising 57 herbs, 8 shrubs, and 13 trees. Species such as Acacia polyacantha and Alstonia boonei among trees, Marantochloa purpurea and Sporobolus pyramidalis among herbs, and Lycium intricatum and Indigofera cuneata among shrubs could be used as potential phytoremediators in African nations for multiple elements, including Ag, As, Au, Cd, Cu, Hg, Mn, Ni, Pb, and Pt. The candidate plant species would reduce hazardous element levels in the environment, decrease the risk of species extinction, and support conservation initiatives. We anticipate that, this review would raise awareness among people about the consequences of mining on the biodiversity and provide baseline data to trigger sustainable remediation efforts in Africa.