VOV.VN - The air quality in the capital on December 7 exceeded the red-warning level, reaching purple, meaning that the air quality of the local atmosphere has reached a very unhealthy level for local residents.

VOV.VN - The air quality in the capital has worsened to dangerous levels, with the air quality index (AQI) rising to between 154 and 155 at 8:00 a.m. on National Day.

VOV.VN - Air quality in the capital has once again worsened to dangerous levels after it previously improved for a short period of time.