Chromium pollution: A threat to environment-A review

In recent years, contamination of the environment by chromium (Cr) has become a major concern. It is unique among the heavy metals found in industrial waste water and sewage and sludge, as it may exist as a trivalent cation and as anion in the hexavalent state in the pH range of agricultural soils. It is used on a large scale in many different industries, including metallurgy, electroplating, production of paints and pigments, tanning, wood preservation, chemical production, and pulp and paper production. These industries are contributing larger amount of Cr, which can ultimately have significant adverse effects on biological and ecological activities of ecosystem. Chromium enters in the food chain through consumption of plant material. A high concentration of Cr has been found to be harmful to vegetation. As the Cr concentration in plants increases, it adversely affects several biological parameters and eventually renders the soil barren.