Refers to atmospheric obscurity caused by fine particles, smoke, or moisture. Often used in weather or environmental contexts.
煙霧のため、遠くの山が見えなかった。
Because of the haze, the distant mountains were not visible.
Smog tends to occur in urban areas.
aerosol
Compound of 煙 (smoke) and 霧 (fog/mist), literally 'smoke-fog'. The exact historical derivation is uncertain, but the spelling is conventionally associated with the meaning.