Question

Lung diseases are about four times more probable in urban areas as compared to rural areas. This is due to the presence of which of the following in the atmosphere?
(A) $C{O_2}$
(B) $N{O_2}$
(C) ${O_2}$
(D) ${N_2}$

Answer 1

To solve this question, we should know which gases are harmful for humans. We can answer this question based on our knowledge about pollution and its types. We can say if we know about air pollution and the pollutants present in air, the correct choice can be made easily.

Complete step by step answer:
In the atmosphere, along with nitrogen, oxygen and traces of carbon dioxide, there are some other components present such as particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone, chlorofluorocarbons and many others. $N{O_2}$ is produced when $NO$ combines with oxygen. When this gas is inhaled, it leads to respiratory issues like asthma, chronic bronchitis, etc. The level of pollutants is high in urban areas as compared to rural areas due to increase in industrialization, traffic, population and housing as well. Humans should control the factors responsible for pollution and should find alternatives to make the planet a better place to live in.
Thus option B. $N{O_2}$ is the correct option to the given question.

Note:
The components, like particulate matter, sulfur dioxide, nitrogen dioxide, carbon monoxide, ozone and chlorofluorocarbons are somehow harmful for humans. For example, when carbon monoxide (CO) is inhaled, it combines with hemoglobin (Hb) to form carboxyhemoglobin. This reduces the oxygen level in the body and results in suffocation and fatal results is death.