Heavy metals in agricultural cultivated products irrigated with wastewater in India: a review

Indiscriminate industrialization and urbanization have negatively impacted our environment. One of the common environmental problems in semi-urban areas in India is the discharge of inefficiently treated municipal, industrial, and domestic wastewater into the environment, resulting in the degradation of soil and water qualities. Depleting freshwater resources have led Indian farmers to look for an easily available, cheaper, and nutrient-rich source of irrigation water in the form of wastewater; however, this also led to increased pollutant transfer to the soils. Known as persistent pollutants, heavy metals such as cadmium (Cd), copper (Cu), chromium (Cr), lead (Pb), mercury (Hg), and a few others are potentially hazardous due to their nonbiodegradable nature, extended biological half-lives, and biological interactions. These heavy metals can bind to soil surfaces and then be absorbed by plant tissues.