Troposphere pollution is generated by unwanted components present in the lowest level of atmosphere.

Oxides of carbon, nitrogen and sulphur hydrocarbons are the main gaseous pollutants. oxides of sulphur $\left(\mathrm{SO}_{2}\right.$ and $\mathrm{SO}_{3}$ ) and oxide of nitrogen $\left(\mathrm{NO}\right.$ and $\mathrm{NO}_{2}$ ) are produced by burning of fossil fules.

This oxide forms nitric acid $\left(\mathrm{HNO}_{3}\right)$ and sulphuric acid $\left(\mathrm{H}_{2} \mathrm{SO}_{4}\right)$ on reacting with oxygen in atmosphere. It will be the reason of acid rain in the end.

$2\mathrm{SO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2} \mathrm{O}_{(l)} \rightarrow 2 \mathrm{H}_{2} \mathrm{SO}_{4(a q)}$

$4\mathrm{NO}_{2(\mathrm{~g})}+\mathrm{O}_{2(\mathrm{~g})}+2 \mathrm{H}_{2} \mathrm{O}_{(l)} \rightarrow 4 \mathrm{HNO}_{3(a q)}$

Acid rain is harmfull to trees and agriculture.

Hydrocarbons are made of hydrogen and carbon and oxides of carbon are obtaine dfrom combusion of its.

Hydrocarbons are carcinogenic and the components made of it are the main pollutants.

$\mathrm{CO}$ is highly poisonous too. Men dies when it mixes into the blood.

$\mathrm{CO}_{2}$ is not poisonous in nature but it performs a major role in global warming. Therefore temperature of earth is increased and ice of north and south ploes melts.

Specific types of smoke, dust, mist, fumes and smog causes the dieses in humans related to respiratory system.