Chapter 4 - Arsenic: environmental contamination, health hazards, and bioremediation approaches for detoxification

Abstract

Arsenic (As) is an abundant element found ubiquitously in nature, primarily in the Earth’s crust and also in the environment. Arsenic is necessary for living beings; however, it is also an emerging issue by virtue of the toxicity it causes in living beings, including humans and animals. Basically, the groundwater is badly affected by As contamination, coming from sources including As-affected aquifers, and has severely threatened humanity around the world. Arsenic poisoning is worst in Bangladesh and Uttar Pradesh, where As(III) is found in higher concentrations in groundwater, which is used by people. The dissolution process caused by oxidation and reduction reactions leads to the natural occurrence of As in groundwater. There are several review articles on As toxicity and exposure, but with scattered information and no systematic knowledge in a combined way. However, in this chapter we try to compile all the information in a systematic manner, which will be helpful for people who are working for As mitigation and removal from the environment for sustainable development. This chapter will be helpful in providing detailed knowledge on As occurrence, speciation, factors affecting As toxicity arising because of its biogeochemistry, and various physicochemical and biological strategies for combating the environmental threats.