ACIDRAIN

Polluted shower (4,4)

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

• Quick crossword No 15,994 — 2021-08-10 23:00:32
  10A: Inca raid (anag) — it's a combination of industrial gas emissions with water in the atmosphere (4,4)
• Quick crossword No 15,905 — 2021-04-28 23:00:13
  2D: Polluted shower (4,4)