Assessment of the Consequences of Xenobiotics in Soil Ecosystem

Basically, the term “xenobiotics” consists of foreign chemical components existing inside any individual as food additives, carcinogens, pesticides, drugs, hydrocarbons, and environmental pollutants. Majority of such xenobiotic components can be applied in air or crop fields, diminishing either in soil or in water bodies, and directly or indirectly pose impact over the persistence of the natural ecology. Usually, such xenobiotics are not identified through various biochemical pathways existing in plants and microbes; therefore, they exhibit the great extent of resistance to degradation. In addition, they also affect the physicochemical stability of soil microenvironment. In soil, the continuous chemical reactions may either convert such xenobiotics into simpler components (mineralization) or occasionally change them into more toxic components (activation). Abovementioned two mechanisms decide the fate of xenobiotics in the soil: either completely mineralized in the soil or will remain stable for long duration (stabilization). Sometimes, such xenobiotic components will degrade and form more toxic compounds or active metabolites from the original one. Small inorganic molecules like H2S, H2O, CO2, and NH3 can also be synthesized through the process of mineralization that occurs in accordance with biotic and abiotic processes. In the present chapter, we have discussed about the various xenobiotic components and their types along with their mechanism of action and treatment techniques with respect to soil ecosystem.