Question

Which of the following will not cause atmospheric pollution?
A. $SO_2$
B. $CO_2$
C. CO
D. $H_2$

Answer 1

Hint: It is a colorless and odorless gas. It can easily be ignited. On igniting it burns with a pale blue which is almost an invisible flame. It is used for refining petroleum, producing fertilizer, treating metals, and processing foods etc.

Complete Answer:
Let us find the correct answer,
Option A is incorrect as sulfur dioxide ($SO_2$) is one of a group of highly reactive gasses known as “oxides of sulfur.” Coal and petroleum often contain sulfur compounds, and their combustion generates sulfur dioxide. Further oxidation of $SO_2$ forms $H_{2}SO_4$, and thus acid rain is formed. This is one of the causes for concern over the environmental impact of the use of these fuels as power sources.

Option B is incorrect as carbon dioxide ($CO_2$) is a greenhouse gas and it has been described as "the leading pollutant" and "the worst climate pollutant". $CO_2$ increase in earth's atmosphere has been accelerating.

Option C is incorrect as carbon monoxide (CO) is a odorless gas emitted from combustion processes. CO can cause harmful health effects by reducing oxygen delivery to the body’s organs (like the heart and brain) and tissues. At extremely high levels, CO can cause death.

Option D is correct as $H_2$ gas does create any pollution.

So, the correct answer is option (D) i.e., $H_2$.

Note: Air pollution costs the world economy about $5 trillion per year. It occurs as a result of productivity losses and degraded quality of life, according to a joint study by the World Bank and the Institute for Health Metrics and Evaluation.