Explain tropospheric pollution caused by oxides of sulphur with suitable examples.

(N/A) When sulphur-containing fossil fuels are burnt,oxides of sulphur are produced.
The most common species,sulphur dioxide $(SO_2)$,is a gas that is poisonous to both animals and plants.
$A$ low concentration of $SO_2$ causes respiratory diseases,e.g.,asthma,bronchitis,and emphysema in human beings. It also causes irritation to the eyes,resulting in tears and redness.
High concentration of $SO_2$ leads to the stiffness of flower buds,which eventually fall off from plants.
Uncatalysed oxidation of $SO_2$ is slow. However,the presence of particulate matter in polluted air catalyses the oxidation of $SO_2$ to sulphur trioxide $(SO_3)$:
$2SO_{2(g)} + O_{2(g)} \rightarrow 2SO_{3(g)}$
The reaction can also be promoted by ozone $(O_3)$ and hydrogen peroxide $(H_2O_2)$:
$SO_{2(g)} + O_{3(g)} \rightarrow SO_{3(g)} + O_{2(g)}$
$SO_{2(g)} + H_2O_{2(l)} \rightarrow H_2SO_{4(aq)}$