Arsenic and iron in water
Topic: Conservation, environmental pollution and degradation, environmental impact assessment.
For prelims: Polluted drinking water, sources and causes.
For mains: Impact on health of Polluted drinking water and ways to treat the water.
Why in news?
- About 3.22 per cent of rural habitations across all states and UTs, accounting for 3.73 per cent of the population, were consuming drinking water with quality issues, according to data tabled by the Ministry of Jal Shakti in Parliament.
Findings of the data reviled by the Ministry:
- Among rural habitations in Indian states, 55,511 face quality issues with drinking water, as of November 27 this year, 3.22 per cent of rural habitations across all states and UTs, accounting for 3.73 per cent of the population, were consuming drinking water with quality issues, according to data tabled by the Ministry of Jal Shakti in Parliament.
- The most affected states of the Country:
- Rajasthan has the highest number of rural habitations affected by contamination overall, at 16,833. Most of these 12,182 are affected by salinity in drinking water.
- In terms of arsenic and iron pollution, West Bengal and Assam are the worst affected. Of the 30,000-odd rural habitations where drinking water is affected by either of these contaminants, over 20,000 are in West Bengal and Assam.
- West Bengal has the highest number of rural habitations affected by arsenic contamination, at 6,207, followed by Assam (4,125), Bihar (804), Punjab (651) and Uttar Pradesh (650). Assam has the highest number of rural habitations affected by iron contamination, at 5,113. It is followed by West Bengal (5,082), Tripura (2,377), Bihar (2,299) and Odisha (2,100).
- States and UTs that are not affected by any of these contaminants include Andaman & Nicobar Islands, Goa, Gujarat, Himachal Pradesh, Ladakh, Manipur, Mizoram, Nagaland, Puducherry, Sikkim and Tamil Nadu.
Causes of Polluted Drinking Water:
- Iron is the most common contaminant of drinking water, with over 18,000 rural habitations affected, and followed by salinity that affects roughly 13,000 rural habitations, arsenic (12,000), fluoride (nearly 8,000) and heavy metal.
- Groundwater contamination occurs when man-made products such as gasoline, oil, road salts and chemicals get into the groundwater and cause it to become unsafe and unfit for human use. Materials from the land’s surface can move through the soil and end up in the groundwater.
- Arsenic contamination of groundwater is a form of groundwater pollution which is often due to naturally occurring high concentrations of arsenic in deeper levels of groundwater.
Impact on Health:
- Long-term exposure to arsenic from drinking-water and food can cause cancer and skin lesions called Black Foot disease.
- It has also been associated with cardiovascular disease and diabetes. In utero and early childhood exposure has been linked to negative impacts on cognitive development and increased deaths in young adults.
- Early clinical symptoms of acute intoxication include abdominal pain, vomiting, diarrhoea, muscular pain and weakness, with flushing of the skin. These symptoms are often followed by numbness and tingling of the extremities, muscular cramping and the appearance of a popular erythematous rash.
Methods to treat arsenic contamination:
- Substitute high-arsenic sources, such as groundwater, with low-arsenic, microbiologically safe sources such as rain water and treated surface water.
- Discriminate between high-arsenic and low-arsenic sources. This can be an effective and low-cost means to rapidly reduce exposure to arsenic when accompanied by effective education.
- Install arsenic removal systems – either centralized or domestic – and ensure the appropriate disposal of the removed arsenic.
- Technologies for arsenic removal include oxidation, coagulation-precipitation, absorption, ion exchange, and membrane techniques.
- The concentration of arsenic and Iron varies dramatically. For a smaller region, the concentration can be very high and for a larger region, it can be spread at a lower concentration. The countries that are significantly affected are Bangladesh, India, China, Taiwan, Vietnam, Argentina, Chile, Western parts of USA and many others.
- It is found that sediments carrying minerals like pyrite are susceptible to an arsenic replacement in its crystal lattice. These sediments when they come in contact with water, in an oxidising environment, form oxyhydroxide rocks that are the principal source of arsenic in reducing waters.
- To curb the issue and provide safe drinking water to the population on a large scale. Majority help as of now can be proper awareness amongst the public about this issue.