Pollution initiates suffocating mist over Galway (4)

I believe the answer is:

smog

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

'initiates suffocating mist over galway' is the wordplay.
'initiates' suggests taking the first letters (I've seen 'initiated' mean this).
The initial letters of 'suffocating mist over galway' is 'SMOG'.

(Other definitions for smog that I've seen before include "Fog polluted by smoke" , "Smoky fog" , "Pea-souper" , "Thick polluted mist" , "Polluted atmosphere" .)

I've seen this clue in The Irish Times.

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