BANGKOK -- At 8 o'clock on Sunday morning, a flight from Harbin, China, operated by regional low-cost carrier AirAsia X was scheduled to land at Don Mueang Airport in northern Bangkok, the airline's hub in the Thai capital.
Pollution stays at unhealthy levels despite weeklong free public transport

Thick smog blankets Bangkok on Jan. 25. According to one pollution index, the air in the Thai capital has been unhealthy on all but eight days this year. (Photo by Yuki Kohara)
BANGKOK -- At 8 o'clock on Sunday morning, a flight from Harbin, China, operated by regional low-cost carrier AirAsia X was scheduled to land at Don Mueang Airport in northern Bangkok, the airline's hub in the Thai capital.