What is Air Pollution?
It is very easy to say that any unfavorable change in the composition of atmosphere which occurs due to the activities of man or some natural event and endangers human life is called air pollution. We know that air is one of the most important components of the environment and is necessary for life, because no living organism can stay alive without it. Man is also dependent on oxygen of atmosphere for respiration like most other living beings. So, if the concentration of oxygen in air is reduced from normal due to the increase in concentration of any other unwanted gas like CO, CO2, SO2, NH3, C12, CH4 etc., the air is said to be polluted and the happening is designated as air pollution. The polluted air can easily spread from one place to another and affect a large population, so, air pollution is very dangerous.
Sources of air pollution
Air pollution sources are mainly of two types: -
Natural sources of air pollution
Natural sources include—forest fire and volcanic eruptions (which liberate smoke, poisonous gases and ashes), dust storms, pollen grains of flowers, fungal spores and microbes etc., carried by air. All these are produced naturally and released in air, making it foul and injurious to human health and also for domestic and forest animals.
Anthropogenic sources of air pollution
The anthropogenic sources of air pollution include the following:
Air Pollution by Industries
There are many types of industries, mainly in the township and cities. Industries such as metallurgical plants, power plants and smelters, chemical plants, petroleum refineries, paper and cotton mills etc., release a variety of inorganic or organic gases in the smoke they produce. In addition, some industries release small particles of dust, carbon, metals etc., and ashes that remain floating in air. All gases and floating particles are harmful for human health.
Air Pollution by Emissions from vehicles
Transport vehicles moving by road, rail, water or air using fossil fuels like coal or petroleum oils produce smoke containing poisonous gases and supply to air pollution. Automobile discharge is a serious problem for cities having heavy traffic on the roads.
Air Pollution by Domestic and institutional sources
Burning of wood or fossil fuels in furnaces and stoves, or running of diesel generators in houses or institutions also produce smoke and pollute the air. Tobacco smoking is also an important source of air pollution in public places like offices, institutions and public transports.
Air Pollution by Agricultural activities
Different types of pesticides, insecticides, fungicides, herbicides etc. are used for spraying in agriculture. These poisonous materials remain floating in air and carried away by the wind making the air unclean for human health as well as for other animals.
Air Pollution by Deforestation
Plants purify the air by removing CO, and adding 0, during the process of photosynthesis. Deforestation, i.e., indiscriminate cutting of trees and cleaning the forests by man for getting wood or urbanization leads to increase in CO, and decrease in O, in the atmosphere, causing air pollution.
Air Pollution by Nuclear explosions and wars
Due to Nuclear explosions and wars emitted radioactive rays which are very harmful for mankind, animals and plants.