Related Clues:
- City hazard
- Row with denials embracing single sweetheart
- Air that can make you cough
- Fog mixed with smoke
- Signal-to-___ ratio
- Contributor to low visibility
- Sound feature: one installed
- Number one seed's cut in half racket
- Snap, crackle or pop
- Southern feline polluting atmosphere
- What plugs protect from
- Dirty 38 Down
- Pollution that often obscures the L.A. skyline
- Emissions concern
- Pollution in city skies