Metal contamination in water resources due to various anthropogenic activities

Abstract

Water is the most fundamental requirement for existence on Earth. There is a natural existence of metals in the water resources but various anthropogenic sources have added immensely to an abnormally high concentration of heavy metals. The main concern with these metals is they show toxicity at very low concentration and also associated with environmental degradation, poor water quality, and different human diseases. They bioaccumulates in the plant and animal system over a period of time by entering through food, air, and water. There are mainly two sources of water pollution, point and nonpoint source (NPS). Injudicious use of fertilizer and pesticide in agricultural practices contributes as NPS pollution to water resources through land run off and has been the source of heavy metals. Industries such as leather, paper and pulp, dye, steel, electroplating, fertilizer manufacture, ore processing and others often discharge untreated wastewater loaded with many criteria metals like Pb, Cd, Cr, etc., into the water and contributes to the point source of water pollution. These metals, once they enter the water, begin to accumulate in the food chain. Some metals also bioaccumulate in animal and human system causing various diseases like Minamata, cancer, etc. To control NPS pollution in water bodies, installation of suitable engineering structures can be undertaken in contaminated area to reduce land runoff. The wastewater generated in industrial facilities has to be treated up to WHO recommended limits before its discharge into water bodies.