Related Clues:
- Hazy pollution
- Some regularly flee rising pollution
- Clean Air Act concern
- L.A. or Houston problem
- Beijing skyline haze
- Bad big city air
- Business mogul conceals air pollution
- Filthy air
- Certain pollutant
- Mexico City problem
- Unhealthy air component
- Delhi problem
- Airborne urban hazard
- Mist in west London area reported
- Urban irritant