What are pollutants such as carbon monoxide and sulfur oxides classified as?

Carbon monoxide and sulfur oxides are classified as primary pollutants because they are emitted directly into the atmosphere from identifiable sources. These pollutants originate from various human activities, such as burning fossil fuels in vehicles, industrial processes, and power plants.

Primary pollutants are characterized by their direct release into the air, where they can cause immediate harmful effects on air quality and public health. In contrast, secondary pollutants are not emitted directly but are formed in the atmosphere through chemical reactions involving primary pollutants and other substances. Tertiary pollutants is not a standard classification in air quality discussions, and organic pollutants refer specifically to a group of compounds that contain carbon and may have toxicological effects, but they do not encompass the broader category of pollutants like carbon monoxide and sulfur oxides. Thus, identifying carbon monoxide and sulfur oxides as primary pollutants accurately reflects their nature and source of emission.