smog
Refers to polluted haze in the air, often from exhaust or industrial pollution; common in compounds such as 光化学スモッグ.
The distant mountains are not visible because of the smog.
In summer, photochemical smog advisories are sometimes issued.
Smog often forms in industrial areas during the summer.
The entire city was covered in smog.
By morning, smog had settled over the town.