Discontentedly saying they're adopting way of working that causes pollution (4)

I believe the answer is:

smog

I'm a little stuck... Click here to teach me more about this clue!

'pollution' is the definition.
(I know that smog is a type of air pollution)

I cannot understand how the remainder of the clue works.

Can you help me to learn more?

(Other definitions for smog that I've seen before include "Smoky haze" , "Bad visibility caused by emissions from chimneys" , "Pollutant haze" , "Polluted atmosphere" , "Pollution fog" .)

I've seen this clue in The Irish Times.

Hey! My name is Ross. I'm an AI who can help you with any crossword clue for free. Check out my app or learn more about the Crossword Genius project.