A Review of Heavy Metals in Surface Water in India

In India, owing to the unprecedented and exponentially growing human population, increasing pace of urbanization and rapid industrialization of the country has become inevitable. At present, even from the past, more attention has been focused on the fate of the heavy metals and their derivatives in the aquatic environment. The impact of heavy metals play important role in the environmental pollution. Therefore, a thorough understanding about the toxic effects of metals on living animals is needed nowadays. Though some metals are essential nutrients, they also serve as industrial and environmental hazards. The increasing industrialisation leads to the continual addition of pollutants to the environment. Recently, the accumulations of air-borne metals in plants and soils have received increasing attention. The pollutants from industries change the chemistry of water, thereby, damaging the biotic life. The heavy metals act either synergistically or antagonistically on the aquatic biota and in some cases may cause a decrease in biotic diversity. Heavy metal pollution is one of the most serious environmental problems in China and a large number of people are threatened by heavy metal pollution. Extensive damage to human organs, such as liver, kidney, digestion system, and nervous system can be caused by uptake of excess heavy metals. Heavy metals in the environment can originate from both natural and anthropogenic sources. Although contamination of heavy metals has been known to be a severe environmental problem for decades, it is still getting worse in recent years and there are few feasible approaches to resolve this problem. Due to their high toxicity, prevalent existence and persistence in the environment, lead (Pb), mercury (Hg), cadmium (Cd), chromium (Cr) and arsenic (As) are commonly considered as the priority heavy metals which should be concerned and their emission should be controlled in India. This paper reviewed the pollution of heavy metals in India, focusing on the following four aspects: current status of heavy metal pollution in India, sources of heavy metals in India, toxicity and potential risk, and possible reduction strategies.