ABSTRACT
Arsenic (As) is a heavy metal (HM) of global concern as it badly prevails in a number of countries causing significantly devastating health hazards. As is present either naturally on Earth's crust or enters into the soil ecosystem chiefly by the application of pesticides which drain out and mix with the groundwater system causing As pollution of water and subsequent accumulation of As by the food crops. Arsenate As(V) and arsenite As(III) are the two forms of As present in the soil. Arsenate, the analog of phosphate can enter the plants through the phosphate transporter causing disruption in the natural processes of plants and its hyperaccumulation in food crops. People get affected by direct consumption of As from food or water sources which triggers multiple diseases and even death. By different strategies of phytoremediation, the harmful HMs can be removed from the environment cost-effectively and in a sustainable way. Various medicinal and aromatic plant species can aid in this process. The advantage of using medicinal plants in the phytoremediation process is that they are generally not consumed and thus the possibility of contaminants entering the food system is minimized. Plants have evolved several systems to cope with As toxicity by using different types of proteins, hormones, and signaling molecules. By studying the mechanism of phytoremediation, genetically improved variety of plants can be produced which will be more efficient in amelioration of the toxic metalloid from the soil and it can ensure the reduction in the uptake of As by the food crops assisting in food safety. This chapter is an attempt to overview phytoremediation of As giving special emphasis on the use of medicinal plants and elaborating overall mechanistic aspects involved in the process.
