Here is your short paragraph on pollution and pollutant !
The word pollution has been taken from the Latin word Pollutionem, meaning defilement from polluere, to soil or defile (make dirty).
Later on Oxford English Dictionary used the word pollute with reference to physical contamination of terrestrial or aquatic environments in the nineteenth century.
In the twentieth century the word pollution was used with reference to contamination of water, soil and air. According to the report of the Environment Pollution Panel of the U.S. President’s Science Advisory Committee (1965), the environmental pollution may be defined as the unfavourable alteration of our surroundings, wholly or largely as a byproduct of man’s actions, through direct or indirect effects, of changes in energy patterns, radiation levels, chemical and physical constitution and abundance of organisms. R.F. Dasmann (1975) has defined pollution as “the accumulation of substances, or forms of energy, in the environment in the quantities, or at rates of flow, which exceed capacity of ecosystems to either neutralize or disperse them to harmless levels”.
In simple words, pollution is an undesirable change in the physical, chemical or biological characteristics of our air; land and water that may or will harmfully affect human life or that of desirable species, our industrial processes, living conditions and cultural assets or deteriorate our raw material resources.
According to Sir Fedrick Warner, “A substance is normally considered to be a pollutant if it adversely alters the environment by changing the growth rate of species, interferes with the food chain, is toxic or interferes with the health, comfort, amenities or property values of people.”
Pollutants may be solids, liquids as well as gases. The solid particulate pollutants include aerosols, industrial wastes, such as lead, mercury, asbestos, etc. The liquid pollutants are dissolved solids, ammonia, urea, nitrates, chlorides, fluorides, carbonates, insecticides and pesticides—all in dissolved form, oil and greases, etc. The major gaseous pollutants are carbon dioxide, sulphur dioxide, nitrogen oxide, etc.