Arsenic contamination in India is a significant environmental and public health issue, affecting various regions across the country. Arsenic is a naturally occurring element that can contaminate groundwater, posing serious health risks when consumed over extended periods. Read here to learn more.
In India, groundwater Arsenic contamination was first identified in 1983 and patients were reported from 3 families in a village of 24 Parganas district in West Bengal. Thereafter many more cases were reported from West Bengal and other States like Bihar, Uttar Pradesh, Jharkhand, Assam, etc.
The problem of high Arsenic levels in drinking water has been observed in parts of the USA, Canada, Argentina, Chile, Mexico, Hungary, and many countries of the Southeast Asia Region which contains a natural Arsenic-rich eco-belt formed by Arsenic-laden alluvium or sediments deposited in the Brahmaputra-Gangetic River basins millions of years ago.
Countries of Southeast Asia that are in this belt include Bangladesh, parts of India, Myanmar, and Nepal.
Arsenic
Arsenic occurs naturally in the environment and can be released into water through natural activities such as hydrothermal action & dissolution of rocks.
- It occurs in both inorganic and organic forms.
- Inorganic Arsenic compounds (such as those found in water) are highly toxic while organic Arsenic compounds (such as those found in seafood) are less harmful to health.
- Shift from surface water and shallow open well sources to deep tube wells in Arsenic affected areas has also led to Arsenic contamination in some States.
- Arsenic leaching may also occur from industrial sources or Arsenic-containing insecticides, herbicides, or rodenticides.
Arsenic is introduced into soil and groundwater during weathering of rocks and minerals followed by subsequent leaching and runoff.
- It can also be introduced into soil and groundwater from anthropogenic sources.
- Arsenic is emitted into the atmosphere by high-temperature processes such as coal-fired power plants, burning vegetation, and volcanism.
- In water, particularly groundwater, where there are sulfide mineral deposits and sedimentary deposits deriving from volcanic rocks, the concentrations can be significantly elevated. Natural low-temperature biomethylation and reduction of arsines also release arsenic into the atmosphere.
Arsenic contamination in India
Arsenic contamination is prevalent in several states in India, with the most severely affected areas located in the Ganges-Brahmaputra delta region.
- States such as West Bengal, Bihar, Jharkhand, Uttar Pradesh, and Assam are particularly impacted.
- The contamination is primarily found in groundwater sources, which many communities rely on for drinking water.
BIS, specification for drinking water (IS10500:2003) specified both values as 0.05mg/l. However, in 2012, BIS reduced the desirable limit of Arsenic from 0.05mg/l to 0.01mg/l while retaining the permissible limit of 0.05mg/l.
Causes of Arsenic Contamination
- Natural Sources: Arsenic contamination in groundwater is often a result of geological processes, where arsenic naturally occurs in certain rock formations. The release of arsenic into groundwater can be influenced by factors such as sedimentation and redox conditions.
- Human Activities: While natural sources play a significant role, human activities like mining, industrial processes, and the use of arsenic-containing pesticides can also contribute to localized contamination.
Read: Groundwater depletion and contamination in India
Health Impacts of Arsenic contamination
Long-term intake of arsenic-contaminated water leads to arsenic poisoning or arsenicosis, with cancer of the skin, bladder, kidney, or lung or diseases of the skin (color changes, and hard patches on palms and soles), or blood vessels of legs and feet.
- Arsenicosis is defined as a chronic health condition arising from prolonged ingestion of Arsenic above the safe dose for at least six months, usually manifested by characteristic skin lesions of melanosis and keratosis, occurring alone or in combination, with or without the involvement of internal organs.
Fresh evidence indicates a possible association between the intake of contaminated water and to onset of diabetes, hypertension, and reproductive disorders.
- Chronic Health Issues: Prolonged exposure to elevated levels of arsenic in drinking water can lead to chronic health issues, including skin lesions, various cancers (particularly skin, lung, and bladder cancers), and neurological effects.
- Vulnerable Populations: Children, pregnant women, and individuals with pre-existing health conditions may be more susceptible to the adverse health effects of arsenic exposure.
Government Initiatives
Water is a state subject, the responsibility of groundwater management, including taking initiatives for improving groundwater quality and mitigating the contamination issue, lies primarily with the state governments. However, several steps have also been taken by the Central Government in this regard.
Water Quality Monitoring: The government has implemented water quality monitoring programs to assess arsenic levels in groundwater and identify contaminated areas.
- Central Pollution Control Board (CPCB) in association with State Pollution Control Boards/Pollution Control Committees (SPCBs/PCCs) is implementing the provisions of the Water (Prevention & Control) Act, 1974, and the Environment (Protection) Act, 1986 to prevent and control pollution in water.
- Department of Drinking Water & Sanitation had launched a National Water Quality Sub-Mission (NWQSM) as a part of the National Rural Drinking Water Programme (NRDWP), which has now been subsumed under JJM, to provide safe drinking water to arsenic/fluoride-affected rural habitations in the country.
Mitigation Measures: Various mitigation measures have been initiated, including the installation of arsenic removal technologies and the promotion of alternative safe water sources.
- The government of India, in partnership with States, has been implementing the Jal Jeevan Mission (JJM) since 2019 to provide potable tap water supply of prescribed quality and on a regular & long-term basis to every rural household in the country.
- Atal Mission for Rejuvenation and Urban Transformation (AMRUT) scheme has been implemented since 2015, in selected 500 cities and towns across the country it focuses on the development of basic urban infrastructure in the AMRUT cities, such as water supply, sewerage & septage management, stormwater drainage, green spaces & parks, and non-motorized urban transport.
- Further, AMRUT- 2.0 was launched in 2021 for the period of 05 years (FY 2021-22 to 2025-26), to provide universal coverage of water supply through functional household tap connections in all statutory towns in the country.
Challenges
- Infrastructure and Resources: Many arsenic-affected areas, especially in rural and remote regions, lack adequate infrastructure for implementing and maintaining arsenic mitigation technologies and water supply systems.
- Financial Constraints: Insufficient financial resources hinder the implementation of large-scale arsenic mitigation projects, especially in economically disadvantaged regions.
- Selecting the right Technologies: Identifying and implementing suitable arsenic removal technologies for specific hydrogeological conditions is challenging. What works in one area may not be effective in another.
- Maintenance and Operation: Sustaining the functionality of arsenic removal technologies requires ongoing maintenance and operational support. Communities may lack the resources or knowledge to maintain these systems.
- Awareness and Education: Lack of awareness about the risks of arsenic exposure and insufficient education on water quality and safety can hinder community participation in mitigation efforts.
- Increased Demand: Population growth in affected regions increases the demand for safe water, adding pressure to existing water supply systems and making it challenging to meet the needs of growing communities.
- Hydrogeological Changes: Climate change can influence hydrogeological conditions, potentially affecting the mobility and distribution of arsenic in groundwater, and complicating mitigation strategies.
Arsenic Removal Technologies
Adoption of arsenic removal technologies, such as activated alumina, iron removal filters, and community-based water treatment plants, is crucial in mitigating the contamination.
- Tapping groundwater from alternate arsenic-free aquifers at a higher depth and proper sealing-off of the arsenic-bearing aquifer from the same. (>100m).
- Large-scale piped water supply for the rural communities by drawing water from the rivers and treating them for removal of pathogenic microbes.
- Conservation and quality upgradation of traditional surface water sources like ponds, dug-wells, etc. in the villages. These sources are generally free from Arsenic but grossly contaminated with fecal pollution.
- Removing Arsenic from the groundwater, by using technologies like adsorption (activated alumina/Iron oxide), co-precipitation (oxidation, coagulation & filtration), or ion exchange.
Way forward
Addressing these challenges requires a holistic and multidimensional approach, involving collaboration between governments, non-governmental organizations, communities, and the scientific community.
Sustainable and context-specific solutions must be developed to ensure the long-term success of arsenic mitigation measures.
- Research and Innovation: Ongoing research and technological innovations are focused on finding cost-effective and sustainable solutions for arsenic removal from groundwater.
- Health Education Programs: Government and non-governmental organizations conduct awareness campaigns and health education programs to inform communities about the risks associated with arsenic-contaminated water and promote safe water practices.
- Community Participation: Involving local communities in decision-making processes and encouraging the adoption of safe water practices are essential components of arsenic mitigation efforts.
Conclusion
Arsenic contamination in India is a complex issue that requires comprehensive and sustained efforts from government bodies, non-governmental organizations, communities, and the scientific community.
Addressing this challenge involves a combination of technological solutions, community engagement, and policy measures to ensure access to safe and arsenic-free drinking water for all affected populations.
-Article by Swathi Satish
Leave a Reply