Air Pollution - Environmental Pollution
The threat due to air pollution became apparent only when some severe episodes caused human casualty in USA, Britain (London) and Japan. In 1948 in Donara town of USA twenty people died and thousands became ill due to prolonged trapping of pollutants in the atmosphere emitted from steel mills and zinc smelter plants. In 1952 nearly 2,500 people died in London when the city got enveloped by sulphuric acid vapours, particulate matter and sulphur dioxide.
The most tragic episode in history occurred in December 3rd, 1984 at Union Carbide in Bhopal when approximately 36 tonnes of methyl isocyanate (MIC), an extremely poisonous gas used in the synthesis of sevin - a pesticide, escaped shortly after midnight from a storage tank and spread like mist and cloud over the city. The poison caught people in their sleep, awakening them in choking pain, terror and panic. Many got killed during sleep. It is estimated that around 10,000 people died and more than 2, 00,000 were injured. Many survivors suffer from permanent respiratory illness and impairment of vision.