Pollution and Pollutants

• Definition of Pollution; Pollution is the undesirable change in the physical, chemical, or biological characteristics of air, water, or soil caused by human or natural activities, which adversely affects living organisms and the environment.
• Scientific Definition (WHO, 1989): “Pollution is the presence of materials in the environment which are harmful to humans and other living organisms or which cause damage to the environment.”

🔹 Definition of Pollutants

• Pollutants are undesirable substances (solid, liquid, or gas) that are introduced into the environment in sufficient quantities to cause harmful effects on life and ecosystem stability.
• Examples: Carbon monoxide (CO), sulfur dioxide (SO₂), nitrogen oxides (NOₓ), plastics, pesticides, heavy metals (lead, mercury), etc.

🔹 Classification of Pollutants

1. Based on Origin

Example: SO₂ + H₂O → H₂SO₄ (acid rain)

2. Based on Degradability

Major Types of Pollution

 1. Air Pollution

Definition: Contamination of the atmosphere due to the presence of harmful gases, dust, fumes, or odors that interfere with human health and the natural environment.

Major Air Pollutants:

Fact: According to WHO (2023), 7 million premature deaths occur annually worldwide due to air pollution.
Indian cities: Delhi, Kanpur, Varanasi, Lucknow are among the most polluted globally.

Control Measures:

• Use of CNG and electric vehicles
• Installation of electrostatic precipitators in industries
• Promotion of public transport
• National Clean Air Programme (NCAP), 2019 aims to reduce PM levels by 40% by 2026

2. Water Pollution

Definition: Contamination of water bodies (rivers, lakes, oceans, groundwater) with substances that degrade water quality and make it harmful for humans, animals, and plants.

Major Water Pollutants:

Fact: India generates 62 billion liters of wastewater per day; only 30% is treated before discharge.

Control Measures:

• Sewage treatment plants (STPs)
• Use of eco-friendly fertilizers and pesticides
• Industrial effluent treatment
• Namami Gange Programme (2014) – river rejuvenation
• Public awareness and waste segregation

3. Soil Pollution

Definition: Contamination of soil by toxic chemicals, salts, pathogens, or waste materials that reduce soil fertility and harm crops and organisms.

Major Soil Pollutants:

Fact: About 147 million hectares of land in India are affected by soil degradation (ICAR, 2023).

Control Measures:

• Use of bio-fertilizers and organic manures
• Recycling of waste
• Phytoremediation (using plants to remove pollutants)
• Strict regulations on industrial waste disposal

4. Noise Pollution

Definition: Unwanted or harmful sound that disturbs human health and environmental quality.

Major Sources:

• Traffic, trains, and aircraft
• Industrial and construction activities
• Loudspeakers and music systems

Effects:

• Hearing loss, stress, hypertension
• Sleep disturbance and decreased concentration
• Negative effects on wildlife (disorientation, migration disruption)

Fact: Noise level above 85 decibels (dB) for long durations can cause permanent hearing damage.

Control Measures:

• Use of silencers and sound barriers
• Tree plantation as natural noise buffers
• Ban on loudspeakers near hospitals and schools
• Noise Pollution (Regulation and Control) Rules, 2000

5. Thermal Pollution

Definition: Increase in water temperature due to discharge of hot effluents from industries and power plants.

Effects:

• Decreases dissolved oxygen in water
• Affects aquatic life and breeding cycles
• Increases algae growth

Control Measures:

• Cooling ponds and cooling towers
• Waste heat recovery systems

6. Radioactive Pollution

Definition: Release of radioactive substances into the environment due to nuclear explosions, power plants, or improper waste disposal.

Sources:

• Nuclear power plants
• Medical X-rays, radiation therapy
• Nuclear weapon testing

Effects:

• Genetic mutations, cancer, radiation sickness
• Soil and water contamination
• Long-term ecological damage

Example: Chernobyl (1986), Fukushima (2011)

Control Measures:

• Safe disposal of radioactive waste
• Use of lead shields
• International Atomic Energy Agency (IAEA) monitoring

 7. Marine Pollution

Sources:

• Oil spills, plastic debris, untreated sewage, ballast water discharge.
• Agricultural runoff carrying fertilizers and pesticides.

Effects:

• Death of marine organisms
• Coral bleaching and ecosystem imbalance
• Accumulation of microplastics in the food chain

Fact: About 8 million tonnes of plastic waste enter oceans every year (UNEP, 2023).

Control Measures:

• Prevention of oil spills
• Ban on single-use plastics
• Marine Protected Areas (MPAs)

Global and National Pollution Control Efforts

International Agreements

Indian Legislation and Programmes

🔹 Preventive and Control Measures (General)

1. Promote eco-friendly technologies
2. Adopt Reduce, Reuse, Recycle (3R) principles
3. Use of clean and renewable energy
4. Public awareness through environmental education
5. Enforcement of environmental laws and penalties
6. Regular environmental monitoring by CPCB and SPCBs

🔹 Important Institutions in India

🔹 Competitive Exam Highlights