Pollution, Land Degradation, Environmental Issues & EIA

1. Land Degradation and Soil Health

Soil Erosion

• Sheet Erosion: Uniform removal of thin soil layers over a large area by runoff
• Rill Erosion: Small channels cut by running water
• Gully Erosion: Large channels cut by concentrated water flow; creates badlands (Chambal Valley is India's classic example)
• Wind Erosion: Common in arid regions — Deflation (removal), Abrasion (sandblasting), Deposition

1. Deforestation — removal of plant cover that binds soil
2. Overgrazing — destruction of ground vegetation
3. Faulty agricultural practices — ploughing along slopes
4. Construction activities
5. Flash floods and heavy rainfall

• Soil erodibility (sandy soils erode faster)
• Slope gradient and length
• Rainfall intensity
• Vegetation cover (the main protective factor)

Methods for Preserving Soil Integrity

1. Contour Farming/Ploughing: Tilling along contour lines perpendicular to slope — reduces runoff velocity
2. Terrace Farming: Step-like platforms cut into slopes — reduces slope length and runoff
3. Strip Cropping: Alternating rows of close-growing crops with row crops — reduces wind erosion
4. Windbreaks/Shelterbelts: Rows of trees planted along field borders to break wind speed
5. Cover Crops/Green Manure: Growing plants like legumes to cover bare soil — binds soil, adds organic matter
6. Mulching: Covering soil with organic material (straw, leaves) — retains moisture, prevents erosion
7. Check Dams: Small dams across ravines to slow water flow and retain sediment
8. Afforestation/Reforestation: Planting trees to restore vegetation cover

Practices for Managing Land Sustainably

1. Integrated Watershed Management: Managing entire catchment area to control erosion and water runoff
2. Organic Farming: Avoiding synthetic pesticides/fertilizers; building soil organic matter
3. Zero-Till Farming: Minimal soil disturbance during agriculture
4. Crop Rotation: Alternating crops to maintain soil fertility (legumes replenish nitrogen)
5. Agro-forestry: Growing trees and crops together for soil conservation
6. Land Use Planning: Designating appropriate land for agriculture, forests, water bodies, and urban use

Desertification

• Climate change (reduced rainfall)
• Unsustainable land use (overgrazing, deforestation)
• Soil loss through wind and water erosion

• India has ~29% of its land undergoing desertification (Desertification and Land Degradation Atlas, SAC-ISRO)
• Rajasthan is the most affected state
• Thar Desert is expanding — converting semi-arid buffer zones to desert
• Also: Bundelkhand region, Deccan Plateau

2. Air Pollution

Primary Pollutants (Directly emitted):

Secondary Pollutants (Formed in atmosphere):

• Ozone (O₃): NOₓ + VOCs + sunlight → ground-level ozone (smog component)
• PAN (Peroxyacyl Nitrates): Eye irritant; formed in photochemical smog
• Sulfuric Acid (H₂SO₄): SO₂ + water → acid rain

Types of Smog:

1. Classical/London Smog: SO₂ + soot + fog; reducing type; occurs in winter mornings; London 1952 Great Smog killed 12,000
2. Photochemical/LA Smog: NOₓ + VOCs + sunlight → O₃ + PAN; oxidising type; occurs in warm afternoons

Air Quality Index (AQI):

• Range: 0–500; Good (0-50) to Severe (401-500)
• SAFAR (System of Air Quality and Weather Forecasting and Research) monitors major Indian cities

Solutions to Air Pollution:

• Transition to EVs (Electric Vehicles)
• BS VI emission norms (Bharat Stage 6)
• Crop residue management (alternatives to stubble burning)
• Clean cooking fuel (LPG, biogas)
• HEPA filters, urban forests as green lungs

3. Noise Pollution

4. Plastic Pollution

• Macro-plastic: Visible plastic items (bags, bottles, packaging)
• Micro-plastic: Particles <5mm; can be primary (microbeads in cosmetics) or secondary (breakdown of larger plastics)
• Nano-plastic: Particles <1 micron; now found in human blood, placenta, lungs

• Marine animals mistake plastic for food → entanglement, starvation, chemical poisoning
• Micro-plastics enter food chain → bioaccumulation and biomagnification
• Detected in deep ocean trenches, Arctic ice, mountain glaciers
• Human exposure: through seafood, drinking water, inhaled air particles

• Single-Use Plastic (SUP) ban from January 1, 2022: Banned 19 categories of SUP <75 microns (straws, stirrers, cups, cutlery, etc.)
• Extended Producer Responsibility (EPR): Manufacturers responsible for post-consumer plastic waste
• Plastic Waste Management Rules, 2016 (amended 2021): Comprehensive framework
• Mission LiFE (Lifestyle for Environment): Promotes reduced plastic use

5. Radiation Contamination

• Ionizing radiation: X-rays, gamma rays, alpha/beta particles — can damage DNA, cause cancer (from nuclear reactors, medical equipment, weapons)
• Non-ionizing radiation: UV rays (ozone depletion increases exposure), microwave, radiofrequency (5G debate, mobile towers)

• Nuclear power plant accidents (Chernobyl 1986, Fukushima 2011)
• Radioactive waste disposal
• Nuclear weapons testing
• Medical radioactive waste

6. Thermal Pollution

• Thermal power plants — use water for cooling; return hot water to rivers/lakes
• Nuclear power plants
• Urban runoff (hot roads and buildings heat rainwater runoff)

• Reduced dissolved oxygen (DO) in water → suffocation of aquatic organisms
• Altered spawning and migration patterns of fish
• Promotes algal blooms and eutrophication
• Increases metabolic rates of cold-blooded animals unsustainably

7. Water Pollution and Ocean Degradation

Sources of Water Pollution:

Key Water Quality Parameters:

• BOD (Biochemical Oxygen Demand): Amount of O₂ consumed by bacteria to decompose organic matter. High BOD = high pollution. Clean water BOD <2 mg/L; Ganga at Varanasi often 15–30 mg/L
• COD (Chemical Oxygen Demand): O₂ required to chemically oxidize all pollutants
• DO (Dissolved Oxygen): Healthy rivers have DO >6 mg/L; <4 mg/L is hypoxic; fish die below 2 mg/L
• pH: Neutral (7) is ideal; acid mine drainage can lower pH to <3

Ocean Pollution:

• Dead Zones: Hypoxic areas in oceans near river mouths — mainly from agricultural runoff (N & P)
• Plastic Gyres: "Garbage Patches" in oceans — Great Pacific Garbage Patch (~1.6 million km²)
• Oil Spills: Coat marine animals, kill seabirds, destroy coral reefs and beaches
• Sound Pollution (Ocean): Shipping noise, sonar testing disrupts whale communication
• Deep Sea Mining: Emerging threat to seamount ecosystems
• Mercury pollution: Bioaccumulates in fish (Minamata disease in Japan, 1950s — methylmercury)

8. Mining Impacts on Environment

Environmental degradation from mining:

1. Land destruction: Open-cast mining creates massive craters — destroys habitat
2. Soil erosion: Exposed, loose overburden material easily eroded
3. Water pollution: Acid mine drainage (pyrite oxidation → H₂SO₄) contaminates rivers and groundwater
4. Air pollution: Dust, particulates, SO₂ from smelting
5. Subsidence: Underground mining causes surface collapse
6. Deforestation: Forest clearance for mining access
7. Displacement: Mining often displaces tribal and forest-dwelling communities (Forest Rights Act issues)

Sand Mining:

• Illegal sand mining is one of India's largest environmental crimes
• Destroys riverbeds — eliminates spawning grounds for fish, nesting sites for turtles
• Leads to river channel deepening → bridge collapse, flooding of farmland
• Lowers water table (dry riverbeds can't recharge groundwater)
• India's sand demand estimated at 2-6 billion tonnes per year — Far exceeds sustainable yield
• Regulation: Supreme Court restrictions; Sand Mining Framework 2020

9. Bioremediation

Types:

1. Bioremediation by Bacteria:
   • Pseudomonas degrades petroleum hydrocarbons
   • Thiobacillus removes sulfur compounds
   • Geobacter reduces uranium contamination
2. Mycoremediation (Fungi):
   • Fungal mycelium absorbs heavy metals and breaks down persistent organic pollutants
   • Pleurotus ostreatus (oyster mushroom) degrades petroleum
3. Phytoremediation (Plants):
   • Hyperaccumulator plants absorb heavy metals from soil
   • Thlaspi caerulescens — accumulates cadmium/zinc; Sunflower — removes cesium/strontium (used at Chernobyl)
   • Water Hyacinth — though invasive, used for phytoremediation of heavy metals
4. Bioventing/Biosparging: Injecting oxygen into contaminated soil to stimulate aerobic bacterial degradation
5. Constructed Wetlands: Using wetland plants to filter and treat wastewater naturally

Applications:

• Oil spill cleanup (Deepwater Horizon 2010 — used Alcanivorax bacteria)
• Mine rehabilitation
• Heavy metal soil remediation
• Industrial effluent treatment

10. Acid Rain (Acid Precipitation)

• SO₂ + H₂O → H₂SO₃ → H₂SO₄ (unstable → sulfuric acid)
• NOₓ + H₂O → HNO₂ → HNO₃ (nitric acid)
• Together form acid rain

• Coal-burning thermal power plants (SO₂)
• Vehicles, industry (NOₓ)
• Volcanic eruptions (natural source of SO₂)

11. Environmental Issues in Focus

Indian Himalayan Region (IHR):

• Covers 10 states: J&K, HP, Uttarakhand, Sikkim, Arunachal, Mehalaya, Tripura, Assam, Nagaland, Manipur, Mizoram
• Key issues: Glacial retreat (Siachen, Gangotri), GLOF (Glacial Lake Outburst Floods), avalanches, landslides, deforestation
• Chamoli Disaster (2021): Flash flood in Rishiganga — linked to glacial lake outburst
• Water tower of Asia: Himalayas feed 10 major river systems including Ganga, Indus, Brahmaputra, Mekong, Yangtze

Palm Oil Issue:

• Palm oil is the world's most widely used vegetable oil (~70 million tonnes/year)
• Environmental problem: Tropical deforestation (Indonesia, Malaysia, Colombia) for palm plantations → biodiversity loss, peat soil burning → massive GHG emissions, orangutan habitat destruction
• RSPO (Roundtable on Sustainable Palm Oil): International certification for sustainable production
• India is world's largest palm oil importer; National Mission on Edible Oils — promoting domestic palm cultivation in NE India and Andaman (raising similar concerns)

Wildlife Deaths:

• Road kills: India — over 22,500 wildlife recorded deaths per year on highways
• Railway lines: NHSRCL (High Speed Rail) threatens elephant corridors
• Electrocution: Agriculture electric fences; high-voltage power lines
• Pesticide poisoning: Raptors, vultures (Diclofenac in cattle carcasses)
• Poaching: Tiger, elephant, rhino, pangolin — biggest issue remains illegal wildlife trade

Human-Animal Conflict:

• Tiger attacks in Sundarbans: Tiger population growing, less space → increasing incursions
• Elephant corridors disrupted: 101 elephant corridors; many bisected by highways, railways, plantations
• Leopard conflict in urban India: Sanjay Gandhi NP (Mumbai) — highest human-leopard conflict globally
• Man-crocodile conflict: Odisha, Assam, Kerala
• Solutions: Electric fences, early warning systems, compensation schemes, eco-sensitive zone (ESZ) enforcement

Genetically Engineered Trees:

• Trees modified to grow faster, resist disease, tolerate cold, or lower lignin (for paper industry)
• Concerns: Gene flow to wild trees, reduced biodiversity (monoculture plantations), ecological disruption
• ArborGen's modified eucalyptus (USA): Cold-tolerant — can invade new regions where natural eucalyptus can't survive
• India: GM crops debated; Bt Brinjal moratorium (2010); GM mustard approved (2022) — controversial

Cost of Environmental Degradation:

• World Bank estimates India loses ~5–8% of GDP annually due to environmental degradation
• TEEB (The Economics of Ecosystems and Biodiversity) framework attempts to value ecosystem services
• Genuine Savings (or Adjusted Net Savings): GDP adjusted for environmental depletion and pollution damage

12. Environmental Impact Assessment (EIA)

Need for EIA:

• Identifies potential environmental impacts early (cheaper to avoid than to remediate)
• Incorporates environmental considerations into project planning
• Provides opportunity for public participation in decision-making
• Ensures sustainable development — balancing economic development and environmental protection
• Legal requirement under Environment (Protection) Act, 1986 in India

EIA Notification India (2006, amended 2020):

EIA Cycle and Procedure:

Components of an EIA Report:

1. Project description
2. Baseline environmental data
3. Alternatives analysis (including "No Project" option)
4. Impact prediction and evaluation
5. Environmental Management Plan (EMP)
6. Risk assessment
7. Public hearing summary

Criticism of India's EIA:

• EIA 2020 Draft: Controversial — reduced public consultation period from 30 to 20 days; allowed post-facto clearance; exempted many project categories; widely criticized by environmental groups