Unit 4: Major environmental issues

Table of Contents

Global Atmospheric Issues

Greenhouse Effect and Global Warming

[Image of the Greenhouse Effect diagram]

Ozone Layer Depletion

Acid Rain

Construction of Dams and Associated Environmental Issues

Large dams are built for hydroelectric power, irrigation, and flood control, but they have significant environmental and social impacts.

Environmental Issues

Social Issues

Case Studies of Environmental Disasters

These are critical examples of the consequences of pollution and industrial accidents.

Disaster What Happened Pollutant / Cause Key Consequence
Bhopal Gas Tragedy (India, 1984) A gas leak at the Union Carbide pesticide plant. Methyl Isocyanate (MIC) gas. Thousands died instantly; many more suffered long-term health effects (blindness, respiratory failure). World's worst industrial disaster.
Minamata Disaster (Japan, 1950s) A chemical factory discharged wastewater into Minamata Bay. Methylmercury. The mercury bio-magnified in fish. People who ate the fish suffered severe neurological damage, paralysis, and birth defects (known as Minamata disease).
Chernobyl Disaster (Ukraine, 1986) A flawed reactor design and human error caused a catastrophic explosion and fire at a nuclear power plant. Radioactive fallout (e.g., Caesium-137, Iodine-131). Massive release of radiation across Europe, acute radiation sickness, long-term increase in thyroid cancer, and a large "exclusion zone."
Fukushima Nuclear Accidents (Japan, 2011) A major earthquake and tsunami disabled the cooling systems of a nuclear power plant, leading to meltdowns. Radioactive fallout. Widespread radiation contamination, evacuation of over 100,000 people, and long-term contamination of the ocean.
Kalpakkam Disaster (India) (Note: This likely refers to various safety incidents or concerns at the Kalpakkam nuclear facility, rather than a single large-scale disaster on par with Chernobyl or Fukushima). Radioactive materials. Concerns about worker safety, environmental contamination, and risks (e.g., from the 2004 tsunami).