$(i)$ Effacts of carbon monoxide :

– Carbon monoxide ($CO$) is one of the most serious air pollutants. It is a colourless and odourless gas.

– It has ability to block the delivery of oxygen to the organs and tissues so it is also highly poisonus for the living organisms.

– Because of incomplete combustion of carbon, carbon monoxide ($CO$) is produced.

Automobile exhaust also released carbon monoxide into the air. Incomplete combustion of coal, firewood, petrol, etc. are also responsible for the production of carbon monoxide.

$\rightarrow$ Carbon monoxide binds hemoglobin to from carboxyhemoglobin. This complex is $300$ times more stable than oxygen-hemoglobin complex.

– In blood, when the concentration of carboxy-hemoglobin reaches about $3-4 \%$ than the oxygen carrying capacity of blood is greatly reduced and because of this headche weak eyesight nervousness and cardiovascular disorder take place. So people are advised not to smoke.

– If pregnant women who have the habit of smoking the increased $CO$ level in blood may induce premature birth, spontaneous abortions and deformed babies.

$(ii)$ Effect of carbon dioxide :

$\rightarrow$ Carbon dioxide $\left(\mathrm{CO}_{2}\right)$ is released into the atmosphere by respiration, burning of fossil fuels for energy, and by decomposition of limestone during the manufacture of cement. It is also emitted during volcanic eruptions.

$\rightarrow$ Carbon dioxide gas is confined to troposphere only. Normally it forms about $0.03$ per cent by volume of the atmosphere.

– With the increased use of fossil fuels, a large amount of carbon dioxide gets released into the atmosphere. Excess of $\mathrm{CO}_{2}$ level in the air maintains by planting green plants.

$\Rightarrow$ Green plants require $\mathrm{CO}_{2}$ for photosynthesis and they emit oxygen, during this process. Because of this the level of $\mathrm{CO}_{2}$ and $\mathrm{O}_{2}$ is maintained.

– Deforestation and burning of fossil fuel increases the $\mathrm{CO}_{2}$ level and disturb the balance in the atmosphere. The increased amount of $\mathrm{CO}_{2}$ in the air is mainly responsible for global warming