Risk of Metal Contamination in Agriculture Crops by Reuse of Wastewater: An Ecological and Human Health Risk Perspective

Abstract

Agriculture sector is one of the major users of water resources. Due to limited availability of freshwater resources, domestic and industrial wastewater is being used in agriculture. Such water and wastewater contain varying number of micronutrients such as carbon and nitrogen as well as other toxic elements. Continuous irrigation with such type of water results overloading of these nutrients and some of the times pathogens, if not treated, in agricultural top soils. Heavy metals are nonbiodegradable and cumulative in nature. The accumulation and bioavailability of the metals depend on various environmental factors such as climatic conditions, temperature, rain pattern, and physicochemical properties of the soil, i.e., organic contents, pH, cationic exchange capacity, etc., which regulate accumulation of metals in soil and its bioavailability. Therefore, such toxic elements once enter in the food chain, get accumulated in various trophic levels, and exert undesirable effects to the flora and fauna. The major concern is its accumulation of toxic metal in agricultural crops from the wastewater-irrigated topsoil and associated health risk to the end-use consumers. Other than ingestion, there are various other routs of heavy metal exposure to the human beings. Therefore, for effective use and management of the wastewater in agriculture, periodic monitoring and risk assessment of heavy metal contamination are very important. This book chapter deals with the comprehensive evaluation of pros and cons of reuse of wastewater in agricultural with special reference to heavy metal contamination and associated human health risk.