UGC NET GUIDE ACADEMY YOU TUBE CHANNEL CLICK FOR VISIT THIS CHANNEL
UGC NET GUIDE ACADEMY YOU TUBE CHANNEL 

DEFINITION Pollution

DEFINITION 
Pollution 

is the effect of undesirable changes in our surroundings that have harmful effects on plants, animals and human beings. 

when only short-term economic gains are made at the cost of the long-term ecological benefits for humanity. 

No natural phenomenon has led to greater ecological changes than have been made by mankind. During the last few decades we have contaminated our air, water and land on which life itself depends with a variety of waste products. 

Pollutants include solid, liquid or gaseous substances present in greater than natural abundance produced due to human activity, which have a detrimental effect on our environment.

The nature and concentration of a pollutant determines the severity of detrimental effects on human health. An average human requires about 12 kg of air each day, which is nearly 12 to15 times greater than the amount of food we eat. 

Thus even a small concentration of pollutants in the air becomes more significant in comparison to the similar levels present in food. Pollutants that enter water have the ability to spread to distant places especially in the marine ecosystem. 

From an ecological perspective pollutants can be classified as follows: Degradable or non-persistent pollutants: 
These can be rapidly broken down by natural processes. 
Eg: domestic sewage, discarded vegetables, etc. 

Slowly degradable or persistent pollutants: Pollutants that remain in the environment for many years in an unchanged condition and take decades or longer to degrade. 

Eg: DDT and most plastics. Non-degradable pollutants: 
These cannot be degraded by natural processes. Once they are released into the environment they are difficult to eradicate and continue to accumulate. 

Eg: toxic elements like lead or mercury. 5.2 CAUSES, EFFECTS AND CONTROL MEASURES OF POLLUTION 5.2.1 
Air PollutionHistory of air pollution: 

The origin of air pollution on the earth can be traced from the times when man started using firewood as a means of cooking and heating. 

Hippocrates has mentioned air pollution in 400 BC. With the discovery and increasing use of coal, air pollution became more pronounced especially in urban areas. 

It was recognized as a problem 700 years ago in London in the form of smoke pollution, which prompted King Edward I to make the first antipollution law to restrict people from using coal for domestic heating in the year 1273. 

In the year 1300 another Act banning the use of coal was passed. Defying the law led to imposition of capital punishment.

 In spite of this airpollution became a serious problem in London during the industrial revolution due to the use of coal in industries. The earliest recorded major disaster was the ‘London Smog’ that occurred in 1952 that resulted in more than 4000 deaths due to the accumulation of air pollutants over the city for five days.


In Europe, around the middle of the 19th century, a black form of the Peppered moth was noticed in industrial areas. 


Usually the normal Peppered moth is well camouflaged on a clean lichen covered tree. 

However the peppered pattern was easily spotted and picked up by birds on the smoke blackened bark of trees in the industrial area, while the black form remained well camouflaged.

Thus while the peppered patterned moths were successful in surviving in clean non-industrial areas, the black coloured moths were successful in industrial areas. 

With the spread of industrialization, it has been observed that the black forms are not only see in Peppered moth, but also in many other moths. 

This is a classic case of pollution leading to adaptation. Chapter5.p65 113 4/9/2004, 5:09 PM 114 Environmental Studies for Undergraduate Courses Air pollution began to increase in the beginning of the twentieth century with the development of the transportation systems and large-scale use of petrol and diesel. 
The severe air quality problems due to the formation of photochemical smog from the combustion residues of diesel and petrol engines were felt for the first time in Los Angeles. 


Pollution due to auto-exhaust remains a serious environmental issue in many developed and developing countries including India. The Air Pollution Control Act in India was passed in 1981 and the Motor Vehicle Act for controlling the air pollution, very recently. These laws are intended to prevent air from being polluted. 

The greatest industrial disaster leading to serious air pollution took place in Bhopal where extremely poisonous methyl isocyanide gas was accidentally released from the Union Carbide’s pesticide manufacturing plant on the night of December 3rd 1984. 

The effects of this disaster on human health and the soil are felt even today.
DEFINITION Pollution DEFINITION   Pollution Reviewed by শ্রী শ্রী সত্যনারায়ণ নমঃ on November 09, 2018 Rating: 5

No comments:

Powered by Blogger.