Polluted, in a way (6)
I believe the answer is:
smoggy
'polluted in a way' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for smoggy that I've seen before include "Hazy, smoky" , "Hazy with pollution" , "Hazy, foggy" , "Like an unhealthy environment" .)