Question

Which is not normally an air pollutant ?
A. CO
B. $SO_2$
C. Hydrocarbons
D. $CO_2$

Answer 1

Pollution is the phenomena that occurs with the release of harmful toxins which damages the environment .And these harmful substances are called as Pollutants.Air pollution is usually caused by toxic or harmful gas emissions or suspended particles.

Complete answer:
Let us analyse the options for finding the correct answer.

Option A : CO i.e Carbon monoxide.And this carbon monoxide is formed when something is burnt.The great source of carbon monoxide iare cars, trucks,and vehicles that have the mechanism of fossil fuel burning.When carbon monoxide is released into the air ,the concentration of oxygen inhaled by the living beings which can cause complications to vital organs such as brain and heart.Hence carbon monoxide is definitely a pollutant and therefore this is the incorrect option.

Option B : $SO_2$ i.e Sulfur dioxide is a colorless , toxic gas which is usually produced by burning fossil fuels such as coal ,oil ,diesel and other sulfur containing materials.Sulfur dioxide is also a byproduct of volcanic activity.Inhaling air polluted with sulfur causes respiratory illness and prolonged exposure can also damage heart and lungs.Along with this sulfur can also cause acid rain that great damage for plants and trees.Therefore this is the incorrect option.

Option C : Hydrocarbons are the organic chemical compounds that are made of hydrogen and carbon.Hydrocarbons are the principal constituents of Natural gas and petroleum. They are also main source of fuel in industries and manufacturing sector.But the problem lies with the incomplete combustion of these hydrogen fuels , which then reacts with Nitrogen oxide to form ozone which is very harmful since it causes skin cancer and other health and environmental issues.Therefore this is the incorrect option.

Option D : Human beings generally release carbon dioxide while respiring and this carbon dioxide is taken up by the plants to perform photosynthesis. Carbon dioxide is considered as greenhouse gas since it helps in the maintenance of temperature on earth’s surface .However anthropogenic release of carbon dioxide disrupts the equilibrium and causes global warming.Therefore this is the correct option.

Hence, the correct answer is option (D)

Note: Air pollution is fast becoming one of the most eminent problems that mankind is facing. And steps such as reducing the usage of private vehicles and using public transport more oftenly reduces the emission of these toxic pollutants and thereby prevents the damage to mankind.