Photochemical smog

Definition

Photochemical smog is an atmospheric condition caused by chemical reactions between sunlight, nitrogen oxides, and volatile organic compounds (VOCs). It results in hazy, brownish-colored air containing high levels of ozone near ground level.

Related terms

Ozone depletion: The reduction in ozone concentration in Earth's stratosphere due to human-made substances like chlorofluorocarbons (CFCs).

Volatile organic compounds (VOCs):

Organic chemicals that easily evaporate at room temperature and contribute to photochemical smog formation.

Nitrogen oxides (NOx): Gases produced by combustion processes such as vehicle emissions or industrial activities that contribute to the formation of photochemical smog.