Question

Define the following:
(i) Pollution
(ii) Smog
(iii) Air pollution
(iv) Noise pollution

Answer 1

(i) Pollution: Any change in the physical, chemical or biological characteristics of soil, air or water, which is harmful for ecosystems and human health and is due to the introduction of organic or inorganic substances in the environment can be defined as environmental pollution. Pollution can be in the form of substances such as toxic chemicals or even in the form of energy, such as noise.

(ii) Smog: It is a combination of 'smoke' and 'fog'. Smog is grimy, dirty, smelly and foul and more dangerous than smoke.When pollutants from automobiles, factories, etc. are released into the atmosphere, they mix with the moisture present in the atmosphere and get suspended in it. This suspended layer of pollutants is called smog.

(iii) Air pollution:Adverse changes in the physical, chemical or biological properties of air are called air pollution. Air pollution occurs when substances like harmful gases, dust, fumes or odour are present in excessive amounts in the air. Air pollutants have the potential to harm our health and comfort or could even cause damage to plants and animals.

(iv) Noise pollution: It is the pollution caused by the excessive production of unbearable sound over a long period of time. It includes noise generated by vehicles on roads, commercial activities, loud music from speakers, etc.