Water pollution is an increasingly pressing environmental issue that poses significant threats to ecosystems, human health, and overall biodiversity. Stemming from various sources such as industrial waste, agricultural runoff, and urban sewage, contaminants infiltrate water bodies, disrupting delicate ecological balances and endangering aquatic life. The ramifications of water pollution extend far beyond aquatic habitats, permeating into the broader environment and impacting human societies through compromised water quality, diminished recreational opportunities, and heightened health risks. As a result, understanding the effects of water pollution is imperative for implementing effective mitigation strategies and safeguarding the integrity of our water resources for future generations.
THERMAL AND RADIATION POLLUTION
- Thermal and nuclear power plants, along with chemical and other industrial facilities, utilize substantial amounts of water for cooling purposes, and the resulting heated water is discharged into rivers, streams, or oceans.
- This discharge of hot water can elevate the temperature of the receiving water by 10 to 15 degrees Celsius above the surrounding ambient temperature, constituting what is known as thermal pollution.
- As water temperature rises, the dissolved oxygen in the water decreases.
- Unlike terrestrial organisms, aquatic organisms are adapted to a consistent and uniform temperature in their environment.
- Sudden increases in temperature can be detrimental, leading to the demise of fish and other aquatic animals.
- An effective approach to mitigate thermal pollution involves storing hot water in cooling ponds and allowing it to cool before releasing it into any receiving water body.
- This helps minimize the adverse effects of elevated water temperatures on aquatic ecosystems.
- In the vicinity of water bodies or during natural calamities such as tsunamis and earthquakes, nuclear accidents pose the imminent risk of radiation leakage (radiation exposure) into the bodies of water.
- A notable example is the Fukushima Daiichi nuclear disaster.
- Exposure to radiation leads to DNA mutations in marine organisms.
- If these mutations are left unrepaired, cells may undergo cancerous development.
- Specifically, the thyroid gland is susceptible to absorbing radioactive iodine, potentially resulting in thyroid cancer.
UNDERGROUND WATER POLLUTION
- In various regions of India, groundwater faces contamination from seepage originating from industrial and municipal wastes, sewage channels, and agricultural runoff.
- Common pollutants found in many parts of the country include fluorides, uranium, heavy metals, and nutrients such as nitrates and phosphates.
- Nitrates, in excess within drinking water, react with haemoglobin to form non-functional methemoglobin, leading to impaired oxygen transport.
- This condition is known as methemoglobinemia or blue baby syndrome.
- Elevated nitrate levels can also contribute to carcinogenesis and accelerate eutrophication in surface waters.
- Trace amounts of metals like lead, mercury, cadmium, copper, chromium, and nickel are prevalent in the groundwater.
- These metals possess toxicity and carcinogenic potential, posing risks to human health.
- The presence of arsenic in groundwater can result from the seepage of industrial and mine discharges, as well as fly ash ponds from thermal power plants.
- In regions such as the Ganges Delta in India and Bangladesh, millions of people are exposed to groundwater contaminated with high levels of arsenic, a highly toxic and dangerous pollutant.
- Chronic arsenic exposure can lead to black foot disease, diarrhoea, as well as lung and skin cancer.
- Excessive fluoride in drinking water causes various health issues, including neuromuscular disorders, gastrointestinal problems, tooth deformities, bone hardening, and painful and stiff joints, a condition known as skeletal fluorosis.
- Knock-Knee syndrome, characterized by pain in bones and joints and outward bending of the legs from the knees, is prevalent in several states due to the consumption of water with high fluoride content, contributing to the widespread issue of fluorosis.
MARINE POLLUTION
- Marine pollution, defined as the release of chemicals into the ocean and its ensuing harmful effects, is a critical environmental concern.
- The discharged chemicals, often potentially toxic, adhere to minuscule particles in the water.
- These particles are subsequently ingested by plankton and benthos animals, including deposit or filter feeders, leading to a concentration of pollutants upward within food chains.
- Consumed food items derived from livestock and animal husbandry may contain toxins due to the high fish meal or fish oil content in typical animal feeds.
- This underscores the potential impact of marine pollution on food safety and human health.
- To address and mitigate marine pollution on a global scale, nations have collaborated to establish two major conventions:
- Convention on the Dumping of Wastes at Sea (to be replaced by the 1996 Protocol): This international agreement aims to regulate the disposal of wastes into the sea, with the 1996 Protocol intended to enhance and replace the original convention.
- United Nations Convention on the Law of the Sea (UNCLOS): This comprehensive treaty seeks to establish legal frameworks for the use of the world’s oceans. UNCLOS addresses various aspects, including marine pollution, and strives to promote responsible and sustainable ocean governance among individual states.
EUTROPHICATION
- Lakes receive their water primarily from surface runoff, which carries various chemical substances and minerals.
- Over the course of millennia, lakes undergo a natural aging process as they accumulate mineral and organic matter, gradually filling up.
- This aging phenomenon is a result of the continuous input of materials carried by water.
- The natural aging of lakes involves nutrient enrichment, fostering the growth of algae, aquatic plants, and diverse fauna.
- This natural process is referred to as natural eutrophication, where the lake evolves over time due to the gradual accumulation of nutrients.
- However, human activities can accelerate the nutrient enrichment of lakes, leading to a phenomenon known as cultural eutrophication.
- This accelerated aging process is a consequence of increased nutrient input, often from human-related sources such as agricultural runoff or discharges from sewage and industrial activities.
Based on their nutrient content, lakes are categorized into three main types:
- Oligotrophic: Lakes with very low nutrient levels.
- Mesotrophic: Lakes with moderate nutrient levels.
- Eutrophic: Lakes that are highly nutrient-rich.
In the context of India, a significant majority of lakes fall into the eutrophic or mesotrophic categories. This is primarily due to the influx of nutrients from their surroundings, as well as the introduction of organic wastes into these water bodies. These factors contribute to the accelerated aging and nutrient enrichment of lakes in the region.
INVASIVE SPECIES
- Water hyacinth plants, often referred to as the ‘Terror of Bengal,’ hold the notorious distinction of being the world’s most troublesome aquatic weed.
- These plants thrive particularly in eutrophic water bodies, where nutrient levels are high, contributing to an imbalance in the ecosystem.
- The rapid and aggressive growth of water hyacinth poses a significant threat to aquatic environments.
- One of the detrimental impacts is the disruption of the ecosystem caused by their prolific multiplication.
- The plants play a role in wreaking havoc by inducing stagnation in polluted water bodies due to their extensive and fast-paced growth.
- In summary, water hyacinth, known as the ‘Terror of Bengal,’ stands out as a formidable aquatic weed that proliferates in eutrophic conditions, disturbing the natural balance of ecosystems and causing water stagnation in polluted environments.
FAQs on Thermal and Radiation Pollution:
1. What is thermal pollution, and how does it occur?
A: Thermal pollution refers to the elevation of water temperature in natural bodies caused by the discharge of heated water from industrial processes. It occurs when thermal and nuclear power plants, as well as other industries, use water for cooling and release the heated water into rivers, streams, or oceans.
2. How does thermal pollution affect aquatic ecosystems?
A: Elevated water temperatures associated with thermal pollution lead to a decrease in dissolved oxygen levels. Aquatic organisms, adapted to consistent temperatures, are negatively impacted, and sudden temperature spikes can result in the death of fish and other aquatic animals.
3. What measures can be taken to mitigate thermal pollution?
A: One effective approach is to store hot water in cooling ponds, allowing it to cool before releasing it into receiving water bodies. This helps minimize the adverse effects of elevated water temperatures on aquatic ecosystems.
4. What are the risks associated with nuclear accidents near water bodies?
A: Nuclear accidents, especially during natural disasters, pose the risk of radiation leakage into bodies of water. A notable example is the Fukushima Daiichi nuclear disaster. Exposure to radiation can lead to DNA mutations in marine organisms, potentially causing cancer.
5. How does radiation exposure affect marine organisms?
A: Radiation exposure causes DNA mutations in marine organisms. If these mutations are not repaired, cells may undergo cancerous development. The thyroid gland, in particular, absorbs radioactive iodine, increasing the risk of thyroid cancer.
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