Lesson 15:Environmental pollution


The word ‘pollution’ is derived from the latin word “polluere” which means to ‘soil’ or ‘defile’. Pollution is the effect of undesirable changes in our surroundings that have harmful effects on plants, animals and human beings.
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.
There are three types of pollutants:

Degradable or non-persistent pollutants: These are rapidly broken down by natural processes. Eg: Domestic sewage, discarded vegetables etc.

Slowly degradable or persistent pollutants: These take decades to degrade and are harmful to the environment. Eg: DDT (Pesticides) and most plastics.

Non-degradable pollutants: These can’t be degraded by natural processes and have harmful effect on human health and environment for several decades. Eg: Toxic substances like lead or mercury and nuclear wastes.


Last modified: Friday, 30 December 2011, 7:10 AM