Ecotoxicological consequences of manganese mining pollutants and their biological remediation

Over the years, mining and metallurgical activities have rapidly influenced the human population. The manufacturing process of manganese (Mn) compounds and their use in industries increased the negative effect on the environment. Therefore, the recovery process of Mn from metal-containing wastes has become very crucial. Mn is a trace mineral found in various forms in the earth's crust and is present abundantly in terrestrial and aquatic environments. Due to the presence of high-level toxicity in surface waters, aquatic organisms exhibit a high-level toxic response. Mn is composed of many minerals such as oxides, sulfates, carbonates, etc. found naturally in the earth. Chronic exposure to this metal pollutant can result in adverse effects and various symptoms related to neurotoxicity including cognitive, Parkinson's disease, manganism, dystonia, and in plants symptoms like chlorosis in leaves and necrotic leaf spots. Mn is released into water bodies, especially through soil erosion, mining activities, and many anthropogenic activities. The toxicity depends on several aspects including the dose, route of exposure, species, and nutritional status of the individual. This element can be considered a systemic toxicant that can damage the multiple organs of humans. These microorganisms will degrade and detoxify the pollutants in the soil, water, and other environments into a non-toxic form that is not harmful to the environment. This review aims to summarize the toxicity of Mn mining pollutants in the environment as well as in humans, plants, and animals and describes the biological remediation strategies. This review also focuses on the environmental Mn pollution and the future aspects to control the Mn pollutants through biological remediation approaches.