Unhealthy smog persisted in most areas of Bangkok and surrounding provinces on Tuesday, as well as in the North, where Muang district of Mae Hong Son was especially afflicted by hazardous dust.
The Pollution Control Department on Tuesday reported that the levels of particulate matter 2.5 micrometres or less in diameter (PM2.5) in Bangkok and its vicinity ranged between 53 and 91 in the morning, exceeding the safety standard of 50 microgrammes per cubic metres in 59 out of 62 air-quality monitoring stations.
In three areas -- Klong Sam Wa in Bangkok, along Navamin Road in Bangkok's Bang Kapi district and tambon Pak Nam in Muang district of Samut Prakan province -- pollution levels hit the red zone, with fine dust measured at 91mcg/m.
In the North, PM2.5 levels were measured at 45-123mcg/m at 17 air-quality monitoring stations. The worst-hit area was in tambon Jong Kham of Muang district in Mae Hong Son, with the fine dust level measured at 123mcg/m.
The department advised people to avoid outdoor activities and wear face masks if going out.