BIOLOGY, POLLUTION

BIOLOGY LECTURE: POLLUTION

1. Meaning of Pollution

Pollution is the introduction of harmful substances (pollutants) into the environment in quantities that cause damage to living organisms and natural resources.

2. Types of Pollution

A. Atmospheric (Air) Pollution

Air pollution occurs when harmful gases, smoke, dust, and chemicals are released into the atmosphere.

FACTORIES → Smoke (CO₂, SO₂) ↓ ATMOSPHERE (Air Pollution) ↓ Humans & Plants Affected

Common Air Pollutants and Composition:

• Carbon monoxide (CO)
• Carbon dioxide (CO₂)
• Sulphur dioxide (SO₂)
• Nitrogen oxides (NOₓ)
• Chlorofluorocarbons (CFCs)
• Particulate matter (dust, smoke)

B. Water Pollution

Water pollution happens when harmful substances enter rivers, lakes, seas, and underground water.

INDUSTRY WASTE → RIVER → DEAD FISH ↑ OIL SPILL / SEWAGE

Water Pollutants:

• Oil spills
• Sewage
• Industrial chemicals
• Fertilizers (nitrates & phosphates)
• Heavy metals (lead, mercury)

C. Soil Pollution

Soil pollution occurs when harmful chemicals contaminate the land.

Pesticides / Chemicals ↓ SOIL ↓ Crops Contaminated

Soil Pollutants:

• Pesticides
• Herbicides
• Plastic waste
• Industrial waste
• Heavy metals

3. Side Effects of Pollution

Effects of Air Pollution:

• Respiratory diseases (asthma, bronchitis)
• Acid rain
• Global warming
• Ozone layer depletion

Effects of Water Pollution:

• Death of aquatic organisms
• Water-borne diseases (cholera, typhoid)
• Shortage of clean drinking water

Effects of Soil Pollution:

• Reduced soil fertility
• Contaminated crops
• Destruction of microorganisms

4. Control of Pollution

Control of Air Pollution:

• Use of clean energy (solar, wind)
• Planting trees (afforestation)
• Proper vehicle maintenance
• Installing filters in factories

Control of Water Pollution:

• Proper sewage treatment
• Avoid dumping waste in rivers
• Control of oil spills
• Industrial waste treatment

Control of Soil Pollution:

• Proper waste disposal
• Recycling plastics
• Reduced use of pesticides
• Organic farming methods

5. Summary Diagram

POLLUTION / | \ AIR WATER SOIL | | | Diseases Dead Fish Poor Crops