Related Clues:
- Air pollution common in big cities
- Dangerous Beijing blanket
- Haze in cities
- City hazard
- Explore underground pool, with most of them swimming
- Air that can make you cough
- Fog mixed with smoke
- Contributor to low visibility
- Southern feline polluting atmosphere
- Dirty 38 Down
- Pollution that often obscures the L.A. skyline
- Emissions concern
- Pollution in city skies
- Delhi issue
- Atmospheric condition that can be caused by wildfires