Course Code: MEVE-019

Course Title: Environmental Issues

Assignment Code: MEVE-019/TMA-01/January 2025 to July 2026

1. Explain the drivers and extent of biodiversity loss.

Ans Biodiversity refers to the variety of life forms at genetic, species, and ecosystem levels. In recent decades, biodiversity has been declining at an alarming rate due to human-induced and natural factors.

Drivers of Biodiversity Loss

The main drivers are often summarized by the IPBES framework (2019) and the Millennium Ecosystem Assessment (2005) as:

1. Habitat Loss and Fragmentation

• Conversion of forests, wetlands, and grasslands into agricultural land, urban areas, dams, and roads.
• Example: Amazon rainforest deforestation for cattle ranching and soy cultivation.
• Leads to fragmentation of habitats, isolating species and reducing gene flow.

2. Overexploitation of Resources

• Overfishing, hunting, poaching, logging, and overharvesting of medicinal plants.
• Example: Overfishing has driven species like Atlantic cod and tuna to collapse.

3. Pollution

• Air, water, and soil pollution degrade ecosystems.
• Pesticides and industrial chemicals cause bioaccumulation and biomagnification (e.g., DDT impact on birds of prey).
• Plastic pollution threatens marine biodiversity.

4. Invasive Alien Species (IAS)

• Non-native species introduced accidentally or deliberately outcompete native species.
• Example: Water hyacinth in Indian water bodies, zebra mussels in the Great Lakes (USA).

5. Climate Change

• Rising temperatures, shifting rainfall patterns, melting glaciers, and sea-level rise alter habitats.
• Coral bleaching due to ocean warming and acidification is a major global threat.

6. Disease and Pathogens

• Spread of diseases in plants, animals, and humans facilitated by trade and climate change.
• Example: Chytrid fungus causing amphibian declines globally.

7. Socio-Economic Drivers

• Population growth, unsustainable consumption, globalization, and weak environmental governance accelerate biodiversity loss.

Extent of Biodiversity Loss

1. Species Extinction Rates
   1. Current extinction rate is estimated to be 100–1000 times higher than the natural background rate.
   1. About 1 million species are threatened with extinction (IPBES, 2019).
2. Ecosystem Degradation
   1. 75% of terrestrial ecosystems and 66% of marine environments have been significantly altered by human activity.
   1. Wetlands are disappearing three times faster than forests.
3. Genetic Diversity Decline
   1. Over 90% of crop varieties have disappeared from farmers’ fields during the 20th century.
   1. Livestock breeds are increasingly threatened; about 17% of domestic breeds are at risk of extinction (FAO).
4. Regional Extent
   1. Tropical regions (Amazon, Congo Basin, Indo-Burma, Himalayas) are biodiversity hotspots but highly threatened.
   1. India: Out of 104,000 species recorded, around 6,800 are threatened (IUCN Red List).

2. Explain the health impacts of Persistent Organic Pollutants and Radioactive wastes. Discuss the management strategies of Persistent Organic Pollutants and Radioactive wastes.

Ans Health Impacts and Management of Persistent Organic Pollutants (POPs) and Radioactive Wastes

Persistent Organic Pollutants (POPs)

POPs are toxic, organic chemical substances that resist environmental degradation, bioaccumulate in living organisms, and biomagnify along food chains.

• Examples: DDT, aldrin, dieldrin, polychlorinated biphenyls (PCBs), dioxins, and furans.

Health Impacts of POPs

1. Endocrine Disruption – Interfere with hormonal systems (e.g., reproductive disorders, infertility).
2. Carcinogenic Effects – Some POPs (dioxins, PCBs) are classified as Group 1 carcinogens by IARC.
3. Neurotoxicity – Affects brain development in children, leading to learning disabilities and reduced IQ.
4. Immune Suppression – Increased vulnerability to infections and diseases.
5. Reproductive & Developmental Effects – Miscarriages, birth defects, and developmental delays in infants.
6. Bioaccumulation Risks – POPs accumulate in fatty tissues, posing long-term chronic health risks.

 Radioactive Wastes

Radioactive wastes are materials containing unstable isotopes that emit ionizing radiation (alpha, beta, gamma rays). They arise from nuclear power plants, medical applications, research labs, and defense activities.

Health Impacts of Radioactive Wastes

1. Acute Radiation Syndrome (ARS): High-dose exposure causes nausea, vomiting, skin burns, and organ damage.
2. Cancer: Long-term exposure increases risks of leukemia, thyroid, lung, and breast cancer.
3. Genetic Mutations: Damages DNA, leading to hereditary diseases in future generations.
4. Organ-Specific Effects:
   1. Thyroid damage (iodine-131)
   1. Bone cancer/leukemia (strontium-90)
   1. Lung cancer (radon gas, plutonium isotopes)
5. Developmental Effects in Children: Growth retardation, congenital malformations, impaired cognitive development.
6. Psychological Stress: Fear of radiation exposure causes trauma, as seen after Chernobyl (1986) and Fukushima (2011) accidents.

Management Strategies

A. Management of POPs

1. International Agreements
   1. Stockholm Convention (2001): Legally binding treaty to eliminate or restrict POPs.
2. Legislation & Policy
   1. Bans on POP pesticides like DDT, aldrin, and PCBs in many countries.
   1. Implementation of pollution control norms in industries.
3. Alternative Practices
   1. Use of Integrated Pest Management (IPM) instead of chemical pesticides.
   1. Promotion of organic farming.
4. Waste Treatment & Disposal
   1. High-temperature incineration to destroy POPs.
   1. Safe storage of POP-containing equipment (e.g., PCB transformers).
5. Public Awareness & Health Monitoring
   1. Educating communities on risks of POPs.
   1. Regular health screening of exposed populations.

B. Management of Radioactive Wastes

1. Classification of Waste
   1. Low-level waste (LLW), Intermediate-level waste (ILW), High-level waste (HLW).
2. Waste Treatment & Storage
   1. Shielded containers for short-lived isotopes.
   1. Deep geological repositories for long-lived HLW.
   1. Vitrification (immobilizing waste in glass blocks).
3. Nuclear Power Plant Safety
   1. Strict operational standards, safety audits, and radiation monitoring.
4. Recycling & Reprocessing
   1. Reprocessing spent nuclear fuel to recover usable uranium and plutonium.
5. Emergency Preparedness
   1. Evacuation plans, radiation shelters, and iodine tablets (for thyroid protection).
6. Regulatory Control
   1. Agencies like IAEA (International Atomic Energy Agency) and Atomic Energy Regulatory Board (AERB, India) ensure safe handling.
7. Public Communication
   1. Transparency in nuclear safety to reduce public anxiety.

3. Discuss the sources, causes, mechanism and process of eutrophication.

Ans Eutrophication is the enrichment of water bodies with nutrients, particularly nitrogen (N) and phosphorus (P), leading to excessive growth of algae and aquatic plants. This process degrades water quality, disrupts ecosystems, and reduces biodiversity.

Sources of Eutrophication

A. Natural Sources (Slow, over centuries)

• Weathering of rocks releasing phosphorus and nitrogen.
• Natural runoff carrying organic matter, sediments, and nutrients.
• Deposition of atmospheric nitrogen from lightning and natural biological fixation.

B. Anthropogenic (Man-Made) Sources (Rapid, severe impact)

1. Agricultural runoff – Fertilizers rich in nitrates and phosphates.
2. Domestic sewage – Human waste, detergents containing phosphates.
3. Industrial effluents – Pulp and paper, food processing, and chemical industries.
4. Aquaculture (fish farming) – Excess feed and fish excreta.
5. Urban runoff – Stormwater carrying nutrients, oils, and organic matter.
6. Atmospheric deposition – Emissions from vehicles, thermal power plants, and industries contribute to nitrogen oxides deposition.

Causes of Eutrophication

1. Excessive nutrient loading – Overuse of fertilizers and detergents.
2. Population growth and urbanization – More sewage and waste discharge.
3. Industrialization – Discharge of nutrient-rich effluents.
4. Deforestation and soil erosion – Increases sediment and nutrient inflow into lakes and rivers.
5. Poor wastewater treatment – Untreated sewage increases organic load.

Mechanism and Process of Eutrophication

The process occurs in sequential stages:

1. Nutrient Enrichment (N and P loading):
   1. Fertilizers, sewage, and runoff increase nutrient concentration in water.
2. Excessive Algal Growth (Algal Bloom):
   1. Nutrient surplus leads to rapid growth of phytoplankton (green, blue-green algae).
   1. Surface blooms block sunlight, reducing photosynthesis of submerged plants.
3. Death and Decay of Plants/Algae:
   1. Algae have short life spans; when they die, they sink to the bottom.
   1. Decomposition by bacteria consumes dissolved oxygen (DO) in the water.
4. Oxygen Depletion (Hypoxia/Anoxia):
   1. Microbial decomposition drastically reduces oxygen levels.
   1. Leads to fish kills, loss of sensitive aquatic organisms.
5. Release of Toxins and Secondary Pollution:
   1. Cyanobacteria (blue-green algae) produce toxins harmful to aquatic life and humans.
   1. Anaerobic decomposition releases foul gases (H₂S, CH₄, NH₃).
6. Ecological Imbalance:
   1. Loss of biodiversity, dominance of hardy species, reduction in water quality, and transformation of lakes/rivers into dead zones.

 Types of Eutrophication

• Natural Eutrophication: Slow, over thousands of years; natural nutrient accumulation.
• Cultural Eutrophication: Rapid, human-induced, due to agriculture, industry, and urbanization.

Consequences (Brief Overview)

• Algal blooms → reduced light penetration.
• Oxygen depletion → fish mortality.
• Water unfit for drinking and recreation.
• Bioaccumulation of toxins in the food chain.
• Economic losses in fisheries and tourism.

4. Discuss the causes, effects and management strategies of soil pollution.

Ans Soil pollution refers to the degradation of soil quality due to the presence of toxic chemicals, wastes, or pollutants that alter its natural composition, fertility, and biological activity, making it unfit for agriculture, ecology, or human use.

Causes of Soil Pollution

A. Natural Causes

• Volcanic eruptions – deposition of ash and heavy metals.
• Soil erosion & sedimentation – transport of pollutants.
• Natural accumulation of salts in arid regions.

B. Anthropogenic (Human-Induced) Causes

1. Agricultural Activities
   1. Excessive use of chemical fertilizers, pesticides, herbicides, and fungicides.
   1. Leaching of nitrates and phosphates into soil.
2. Industrial Activities
   1. Improper disposal of industrial effluents, heavy metals (Pb, Hg, Cd, As), and chemicals.
   1. Mining activities releasing toxic tailings.
3. Urbanization and Solid Waste Disposal
   1. Dumping of municipal solid waste, plastics, e-waste, biomedical waste.
   1. Landfills leaching hazardous substances into soil.
4. Deforestation and Construction
   1. Removes protective vegetation, causing soil erosion and exposure to pollutants.
5. Radioactive Waste
   1. Leakage from nuclear power plants or medical waste disposal.
6. Oil Spills and Hydrocarbons
   1. Leakage from petroleum industries and transport systems.

Effects of Soil Pollution

A. On Environment

• Loss of soil fertility due to chemical imbalance.
• Soil erosion and desertification from degradation.
• Disturbance of soil microbial balance.
• Leaching of pollutants contaminates groundwater and surface water.

B. On Agriculture

• Reduced crop yield and quality.
• Accumulation of toxic chemicals in food crops.
• Increased dependence on fertilizers to maintain productivity.

C. On Human Health

• Heavy metals (Pb, Cd, Hg) cause neurological disorders, kidney and liver damage.
• Nitrate contamination leads to methemoglobinemia (blue baby syndrome).
• Carcinogenic compounds from pesticides (e.g., DDT, benzene derivatives).
• Respiratory issues and skin diseases from direct contact.

D. On Ecosystems

• Bioaccumulation and biomagnification of toxins in food chains.
• Reduction in biodiversity of soil organisms (earthworms, microbes).
• Loss of ecological balance in terrestrial ecosystems.

Management Strategies for Soil Pollution

A. Preventive Measures

1. Sustainable Agriculture
   1. Use of biofertilizers and biopesticides instead of synthetic chemicals.
   1. Adoption of organic farming and crop rotation.
2. Waste Management
   1. Proper treatment of industrial effluents before disposal.
   1. Segregation and recycling of municipal solid waste.
   1. Safe disposal of hazardous and biomedical waste.
3. Legislation and Policy
   1. Enforcement of environmental protection laws (e.g., Hazardous Waste Management Rules in India).
   1. Bans on persistent pesticides and harmful chemicals.

B. Remediation Strategies

1. Bioremediation – Use of microbes to degrade organic pollutants.
2. Phytoremediation – Use of plants (e.g., sunflower, vetiver grass) to absorb heavy metals.
3. Soil Washing and Thermal Desorption – Removal of contaminants using physical/chemical techniques.
4. Composting and Organic Amendments – Restoring soil fertility.
5. Land Reclamation – Using gypsum/lime to neutralize acidic or saline soils.

C. Awareness and Education

• Public campaigns against plastic use.
• Promoting eco-friendly products and practices.

5. Discuss the causes, impacts and management of inland water pollution.

Ans Inland water pollution refers to the degradation of rivers, lakes, ponds, reservoirs, and groundwater due to the discharge of harmful substances (organic, inorganic, or biological). It alters the physical, chemical, and biological properties of water, making it unfit for drinking, irrigation, aquatic life, and other uses.

Causes of Inland Water Pollution

A. Domestic Sources

• Untreated sewage containing organic waste, detergents, and pathogens.
• Discharge of household chemicals and plastics.

B. Agricultural Sources

• Runoff of fertilizers (nitrates, phosphates) causing eutrophication.
• Pesticides and herbicides contaminating surface and groundwater.
• Livestock waste entering water bodies.

C. Industrial Sources

• Effluents from textile, tanneries, pulp and paper, chemical, and pharmaceutical industries.
• Heavy metals (lead, mercury, cadmium, arsenic) contaminating water.
• Thermal pollution from industries and power plants.

D. Urbanization and Development

• Solid waste dumping into rivers and lakes.
• Construction activities causing siltation and sedimentation.
• Oil spills from transport and shipping.

E. Other Causes

• Mining activities releasing acidic drainage.
• Religious and cultural practices – immersion of idols, flowers, plastics.
• Groundwater contamination by leaching of landfills, septic tanks, and chemical spills.

Impacts of Inland Water Pollution

A. Environmental Impacts

1. Eutrophication – Excess nutrients → algal blooms → oxygen depletion → fish kills.
2. Loss of biodiversity – Decline in sensitive species of fish, amphibians, and invertebrates.
3. Alteration of ecosystems – Favors growth of hardy, invasive species.
4. Groundwater contamination – Persistent pollutants like nitrates and heavy metals affect aquifers.

B. Human Health Impacts

1. Waterborne diseases – Cholera, dysentery, hepatitis, typhoid.
2. Toxic effects – Heavy metals cause neurological, kidney, and liver damage.
3. Nitrate poisoning – Causes blue baby syndrome (methemoglobinemia).
4. Carcinogenic effects – Industrial chemicals (e.g., benzene, arsenic) linked to cancer.

C. Socio-Economic Impacts

1. Loss of drinking water resources.
2. Decline in fisheries and aquaculture productivity.
3. Reduction in tourism and recreational activities.
4. Economic burden – Increased cost of water treatment and healthcare.

Management of Inland Water Pollution

A. Preventive Measures

1. Wastewater Treatment
   1. Construction of sewage treatment plants (STPs).
   1. Treatment of industrial effluents before discharge.
2. Agricultural Management
   1. Use of biofertilizers and organic manure.
   1. Adoption of integrated pest management (IPM).
   1. Controlled use of fertilizers to reduce runoff.
3. Urban Planning
   1. Proper solid waste management to prevent dumping into rivers/lakes.
   1. Development of storm water drainage systems.

B. Remediation Strategies

1. Bioremediation – Use of microbes to degrade organic pollutants.
2. Phytoremediation – Aquatic plants (water hyacinth, duckweed) absorb heavy metals.
3. Aeration of water bodies – Restores dissolved oxygen.
4. Desilting and dredging – Removes contaminated sediments from lakes and rivers.
5. Wetland restoration – Acts as a natural filter for pollutants.

C. Policy and Governance

• Implementation of Water (Prevention and Control of Pollution) Act, 1974 in India.
• National River Conservation Plan (NRCP) and Namami Gange Programme.
• Monitoring by Central Pollution Control Board (CPCB).

D. Awareness and Community Participation

• Public campaigns against dumping of waste in water bodies.
• Community-based river/lake cleaning initiatives.
• Promotion of eco-friendly practices in festivals and agriculture.