According to a recent report by the Center for Science and Environment (CSE), India’s rivers are witnessing severe metal pollution. Substantial levels of toxic heavy metals such as lead, iron, nickel, cadmium, arsenic, chromium, and copper have been detected at three out of every four river monitoring stations.
Heavy Metals and Their Pollution
Heavy metals, defined as elements possessing an atomic number larger than 20 and an atomic density greater than 5 g cm-3, exhibit metal-like characteristics. These include arsenic, cadmium, chromium, copper, lead, manganese, mercury, nickel, uranium, amongst others.
Heavy metal pollution in rivers, soils, and the environment is primarily due to rapidly expanding agriculture and metal industries, improper waste management, excessive fertilizers and pesticides use. Primary sources of heavy metals in groundwater include industrial and agricultural activities, landfilling, mining, and transportation. Discharge of wastewater from industries like the tannery industry, which emits chromium heavy metals, exacerbates the issue.
Sources of Heavy Metals
Heavy metals enter the environment via two main routes—natural and anthropogenic sources. Naturally, heavy metals are present within the earth’s crust and in rocks as minerals. Anthropogenic sources, on the other hand, pertain to human activities like mining, industrial operations, and agriculture. These activities often result in heavy metals getting released into surroundings or deposited on land.
Monitoring and Analysis of Heavy Metal Pollution
In India, there are 764 river quality monitoring stations spread across 28 states. Out of the 33 stations monitoring the Ganga river, ten sites exhibited high levels of heavy metal contaminants. A study conducted by the Central Water Commission between August 2018 and December 2020 revealed inadequate wastewater treatment, with high levels of total coliform and biochemical oxygen demand observed at many stations. Unsurprisingly, the CSE’s State of the Environment Report 2022 highlighted that ten states do not treat their sewage at all, with 72% of sewage waste being dumped untreated across the country.
Impacts of Heavy Metal Pollution
Heavy metal pollution has adverse effects on the environment and living beings, leading to bioaccumulation and biomagnifications. Bioaccumulation refers to the collective accumulation of pollutants in an organism from various sources. In contrast, biomagnification pertains to the increased concentration of chemicals in organisms due to exposure to polluted water and food. These heavy metals adversely affect biological activities and growth and can accumulate in organs, causing severe diseases like cancer, skin ailments, nervous system disorders, and more. They are also responsible for DNA damage, developmental retardation, renal damage, and in extreme cases, death.
About the Namami Gange Mission
In response to rising pollution levels, the Indian government launched the Namami Gange Mission in June 2014. It is an integrated conservation mission aimed at abating pollution and conserving and rejuvenating the Ganga river. The program operates under the Department of Water Resources, River Development and Ganga Rejuvenation, Ministry of Jal Shakti, and implements through the National Mission for Clean Ganga (NMCG) and its state counterpart organizations.
The Role of Central Water Commission
The Central Water Commission (CWC), an attached organization of the Ministry of Jal Shakti, plays a crucial role in controlling, conserving, developing, and utilizing water resources across India for purposes like irrigation, flood management, power generation, and navigation. They work in consultation with State Governments, initiating and coordinating schemes for water resource development.