Air Pollution – Effects of domestic & Industrial Wastes
The major problem that the atmosphere is being subjected to is pollution. In India, about 100 million tons of pollutants are being added to the atmosphere annually. This figure is likely to go up in future. Polluted air is harmful to man and the biosphere on the whole, as well. This problem needs to be tackled urgently. Since all of us contribute to it directly or indirectly, we must study air pollution in detail and discuss the means of controlling and preventing it.
Air pollution can be defined as ‘the change of composition of air by the addition of harmful substances like the industrial and automobile gases and particulate matter.’
Sources of Air Pollution
Most of the sources of air pollution are related to man’s activities as a result of the modern lifestyle. Added to this are also natural causes like the volcanoes, anaerobic decomposition of organic matter, atmospheric reactions, etc.
Burning of Fossil Fuels
Fossil fuels include petroleum and coal. Burning of coal produces a lot of smoke and dust whereas burning of petrol mainly produces sulphur dioxide. In addition to these, the pollutants include carbon monoxide (CO), carbon dioxide (CO2), nitrogen oxides, hydrocarbons, particulate matter and traces of metals.
Petrol on combustion produces carbon monoxide, hydrocarbons, nitrogen oxides, aldehydes, sulphur compounds, organic acids and ammonia and carbon particles. Incomplete combustion of petrol produces a hydrocarbon, 3,4 benzpyrene. There is more pollution during acceleration and deceleration than during constant speed.
They produce oxides, sulphur, nitrogen, hydrocarbons, particulate matter and fluorine.
Since they are coal based the pollutants are fly ash, soot and sulphur dioxide.
They produce cotton dust, nitrogen oxides, chlorine, naphtha vapours, smoke and sulphur dioxide.
They produce carbon monoxide, carbon dioxide, sulphur dioxide, phenol, fluorine, cyanide, particulate matter, etc.
Volcanic eruptions release oxides of nitrogen that pollute the atmosphere.
Decomposition of organic matter under anaerobic conditions produces methane which on being oxidised in the atmosphere produces carbon monoxide. Decomposition of these matter also produces foul smelling gases.
Photochemical oxidation of marine organic matter and biological oxidation by marine organisms produce lot of carbon monoxide on the surface of the oceans which enters the atmosphere.
There are six main categories of air pollutants:
• oxides of carbon
• sulphur dioxide
• oxides of nitrogen
• inorganic particulate matter and aerosols
• organic particulate matter
Effects of Air Pollution