Overview on Occurrence of Arsenic on Human Health and Its Removal Through Microorganisms

Arsenic is a tremendously harmful metal that exists naturally in the environment and is also discharged from anthropogenic sources. It is released into the air by high-temperature procedures such as volcanic eruptions, burning plants, flora, and coal-fired power plants. Recent studies have demonstrated the worldwide occurrence of arsenic in various ecosystems at elevated levels, culminating in contamination in foods and water. Chronic long-term exposure to arsenic causes cardiovascular, pulmonary, and renal diseases, unfortunate pregnancy consequences, newborn death, and cancers of different organ systems. This has resulted in a plethora of effective and viable physico-chemical and biological strategies for the removal of arsenic. Among all the removal methods, bioremediation, involving the use of microorganisms is the most efficient, owing to several advantages such as cost-effectiveness and environmental safety, with limited resources. In this context, this article presents a brief overview of the occurrence and toxicity of arsenic on human health in order to substantiate the importance of its removal from the polluted environment. Additionally, it also focuses on bioremediation of arsenic-contaminated samples by micro-organisms such as bacteria, fungi and microalgae. These microorganisms are known to interact with arsenic by numerous mechanisms such as biosorption, redox reactions, methylation, and bioaccumulation. A detailed analysis of these mechanisms is provided along with the latest literature reports.