SMOG

Air pollution (4)

Solution has appeared in 3 crosswords (2 across and 1 down):

• Quick crossword No 15,985 — 2021-07-30 23:00:13
  7A: Air pollution common in big cities (4)
• Quick crossword No 15,854 — 2021-03-01 00:00:08
  20D: Atmospheric pollutant (4)
• Quick crossword No 15,239 — 2019-03-12 00:00:25
  8A: Air pollution (4)