What are the primary sources of air pollution?

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Dense smog and orange haze blanket the skyline of Mexico City at sunset, with buildings in the Polanco neighborhood partially obscured by air pollution. — air pollution Pollution darkening the skies over Mexico City.

Primary sources of air pollution include emissions from automobiles, power plants, and factories. Wildfires also contribute directly to atmospheric contaminants. These primary pollutants, such as sulfur dioxide, nitrogen oxides, and carbon monoxide, can then react in the atmosphere to form secondary pollutants like ozone and acid rain. Agricultural activities also release pollutants, including pesticides, odors, smoke, and dust. In urban areas, construction sites and unpaved roads can be significant sources of dust.12345