Los Angeles woe (4)
I believe the answer is:
smog
'los angeles woe' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for smog that I've seen before include "Smoky haze" , "Smokey fog" , "Pea-souper" , "Thick polluted mist" , "Pollutant haze" .)