Define air pollution. Enlist natural and manmade air pollution

 Define air pollution. Enlist natural and manmade air pollution. What are the effects of air pollution on human, plant and materials ?

Solution:

Air pollution: When the air gets contaminates with such substances so that the resulting air poses life threat to human and other living organisms then this is called as air pollution. These substance which pollute the air are called as air pollutants.

Natural air pollution :

 Natural air pollution is caused due to:

(i) Duststroms

(ii) Volcanoes spreading ash and other toxic gases in the environment

Man made air pollution: Manmade air pollution is caused due to:

(i) Emission from automobiles

(ii) Industrial emission

(iii) Dust originating from construction sites

(iv) Open air burning of agricultural wastes and other refuse

(v) Excessive use CFC as refrigerant

(vi) Burning of coal in thermal power plants

Effects of air pollution : 

Air pollution has many hazardous effects on human, plants and other living beings. These are enumerated below:

(i) Sulphur dioxide causes irritation when inhaled and has an adverse effect on the mucous membrane. It increases the breathing rate and causes oxygen deficiency.

(ii) Hydrogen sulphide is a foul smelling gas and cause headache, sleeplessness and conjunctivitis along with pain in the eye. Higher concentration of this pollutant may lead to blockage of oxygen transfer in humans.

(iii) Carbon monoxide: It results due to incomplete combustion of coal. When inhaled, it replaces oxygen in hemoglobin and forms carboxy – hemoglobin (CO.Hb) and thus human tissues gets devoid of oxygen which may lead to death.

(iv) Oxides of nitrogen: There area total of five oxides of nitrogen viz N2O,NO,NO2,NO3 and N2 O5. Among these, only the NO and NO2 are injurious to human health. These cause nasal and eye irritation along with respiratory disorder.

(v) Lead: lead cause irritation to mucous membranes of nose, throat and lungs. Lead has fatal effect on gastrointestinal tract, kidney and lever. It retards mental growth.

(vi) Fluorides: hydrogen fluoride and other fluorides cause fluorosis in cattle.Certain varieties of fluorides are highly irritant and corrosive in nature.

(vii) Benzene: Benzene and other aromatic hydrocarbons cause canser.