What happens when the threat of exposure to dirty air is reduced in a community?

there is enough oxygen available for people’s lungs to function normally.

the amount of indoor air pollutants released during a fossil fuel burn decreases.

there is a minimal exposure risk to the outdoor dirty air pollutants, carbon monoxide and radon.

the risk of experiencing digestive related diseases from exposure to a buildup of dirty air is low.

Air pollution is due to a mixture of solid particles and gases in the air. This is caused by various polluting factors, among which are carbon monoxide emissions from automobiles, nitrogen oxides, chemical compounds from factories, dust and ozone.

In this context, the inhalation of these toxic components increases the chances of having health problems, even death. However, when these conditions are improved by removing pollutants and taking actions to purify the air; the life quality of the people who breathe it improves as well.

Therefore, there is enough oxygen available for people’s lungs to function normally.

a and b because with the other three, they simplify to something else.